If you've entered an instance and received the message "Additional instances could not be launched. Please, try again later," you have seen first-hand the new instance performance balancing system that has been implemented to limit the total number of instances that can be created on each realm. Wryxian on the official European forums has supplied the following information :

This update instituted a load check that limited opening of additional instances. This will result in throttling of some instance creation. ... Ultimately, we felt that some wait time for players attempting to create a new instance was better than causing bad performance for all players in instances.

Wryxian also said Blizzard will continue to collect data and their ultimate goal is to remove the instance limit. You can read the full post below.

Bornakk has listed some recent fixes on the official forums that have been applied today to the game:

Icy Prisms should now be unique, they cannot be mailed but can still be traded.

The Rogue ability Mutilate should now do its appropriate damage based on talents.

As we reported yesterday, the European World of Warcraft site is sharing some Ulduar information on its "under development" page. Well, according to Daelodev on the European forum, it's getting close to the point where Ulduar boss battles will be added to the PTR with patch 3.1.0. Ulduar will be off by default, but specific bosses will be enabled so players can try them out.

Shortly after 3.1.0 PTR is up and running, I'll post a schedule that will indicate when we will open specific bosses to testing. We'll have testing opportunities for both EU and NA region PTRs in their respective prime time playing hours. There might also be a boss or two we do leave up for extended testing, and some bosses will only be tested in either the EU or NA. Some encounters won't be up on the PTR at all! There's 14 boss encounters in Ulduar, there will be lots to test.

The first set of enabled bosses will include Freya, Thorim, Hodir and The Iron Council. The official PTR forum will contain updates on the scheule as we get closer to testing. You can read Daelodev's full post below.

The World of Warcraft European site has given us a glimpse into Ulduar on its "Under Development" page. Some gamers have voiced concerns that end-game content in Wrath of the Lich King is too easy, and the developers have said that Ulduar will be a true challenge. What do you think?

Many players have already gotten their Wrath of the Lich King raiding feet wet in Naxxramas and the Sartharion raid, but Ulduar is the first example of the expansion's much larger, truly epic scope of raiding, as will be evident from the second you set foot in the instance. The most obvious difference between Ulduar and its predecessors is that the dungeon actually comprises two separate raid areas. The first section is an epic battle against a vast army standing between you and the entrance of the dungeon proper; in the second area, you will dive into the heart of the dungeon itself and finally discover the secrets of Ulduar.

You can keep reading all about Ulduar below.

That's right! BlizzCon was just announced and it will be taking place this year from August 21st to August 22nd at the Anaheim Convention Center just outside of Los Angeles. It's interesting that Blizzard would move the event earlier this year, but at the same time they're giving fans more space by opening up all four halls of the convention center. At this time, Blizzard has not gone into any specifics about what they'll be showing; though it's safe to assume that Diablo III and StarCraft II will be available for players. Additionally, it's entirely possible that Blizzard will announce their second MMO in development as they've recently begun talking about it more. Lastly, it's possible that four halls leaves enough room for four games. Could this mean that the third World of Warcraft expansion will be announced or on display? I suppose we'll find out in August.

After last years BlizzCon ticket fiasco; it's rumored that Blizzard will be using Ticketmaster to handle ticket sales. You can expect to find ticket information on the official BlizzCon site as the event approaches.

We had a great time at last years show and if you missed our coverage, make sure to check it out. Stay tuned for more information as it becomes available. Click here for the press release at Blizzards EU website.

If you have the Alliance or Horde Epic Collection Steins sitting on your shelf, you'll be happy to hear that a third stein will be released in April showcasing the Rise of the Lich King. The stein will feature the artwork of fantasy artist Alex Horley.

The new Rise of the Lich King stein will prominently feature the malevolent Lich King Arthas Menethil, the central figure in Blizzard Entertainment’s recent Wrath of the Lich Kin expansion set, along with his undead army.

And it you're still looking for more steins, 3 Point Entertainment will be releasing a Legendary Collection of high-end limited edition variants of their Epic Collection Steins. For more information, visit wowsteins.com or read the press release after the jump.

World of Warcraft celebrated the 4-year anniversary of its European launch this week and Blizzard is holding a ton of contests to celebrate. You can find out all about them here or keep reading below for some more details.

Join in our first ever World of Warcraft T-Shirt Design Contest , where the grand prize winner's design will be printed on a limited edition run of t-shirts and sold in our Blizzard Store! Additionally, you can participate in the Four Years of World of Warcraft Fan Art Contest and you could win an XPS 1730 laptop from Dell, $65 (USD) worth of free shipping on items of your choice from SwagDog, a murloc plushy, six months of World of Warcraft game time, and a Gurky, the baby murloc key! Also, for our lore buffs out there, we have a Lore Contest where, by showing off your knowledge of World of Warcraft, you can win an XPS 1730 laptop from Dell, a murloc plushy, six months of World of Warcraft game time, and a Gurky, the baby murloc key!

So how's everyone enjoying the Love is in the Air event? If you need help completing any of the achievements, Allakhazam poster The rusttle of Doom has provided some helpful hints in our general forum. The event ends Monday, so enjoy playing this weekend if you have time.

Of course, if world events aren't your thing, Blizzard has provided another form of Valentine's Day entertainment for you. The team has posted some new player-submitted stories on the official WoW site and the theme is, as one would expect, love. If you'd like to submit your own story, all of the information can be found here.

Jeff "Tigole" Kaplan has officially left the World of Warcraft team to work on Blizzard's upcoming, unannounced MMO. Kaplan said WoW has been a major part of his life for six and a half years. He served as the spokesperson and Game Director for World of Warcraft on Wrath of the Lich King, and our very own Tamat had the chance to speak with him at the WotLK release party back in November. In his farewell post, Kaplan thanks the WoW development team and the players. He also touches very briefly on the unannounced Blizzard MMO:

When all is said and done, WoW is still my favorite game. I play it every day. None of that passion is gone. If anything, it fuels the challenge of making our next MMO even better. We know we have some big shoes to fill.

Perhaps the only company that can create the WoW-killer is Blizzard itself. Regardless, we wish Tigole the best of luck in his new role. You can read his full farewell post after the jump.

The WoW community has been abuzz for awhile now over the possibility of being able to dual spec in the future, and how it might work. Blizzard has posted a Q&A with Greg "Ghostcrawler" Street with some answers to questions over this exciting new feature, and he hints at it hitting the PTR soon as well.

Keep reading after the jump for the full Q&A or discuss it in the Allakhazam forums here.

Talent Dual Spec Q&A with Ghostcrawler
With the next content patch, we will be introducing a number of additions and changes to the game. One new feature in the works is the ability to set up two separate sets of talents, or "dual spec". While the complete feature may not be immediately available in the Public Test Realms (PTR) and specifics are still liable to change, we wanted to go over some questions with Senior Game Designer Greg "Ghostcrawler" Street to find out more.