DAoC is alive on well on its last remaining server.
There is really only one server left, Ywain. As the poster above said, you actually have to choose Ywain1-Ywain10, but the 1-10 are just for housing. All other aspects are shared. Only Ywain1 housing is close to being full. It is easy to get premium housing lots in any other zone.
As for changes to the game in 8 years, the game is only 8.5 years old, so if you have not played since 2002, then there are too many changes to name.
The most important things for newer players to know now, is that most top end gear can be purchased now through using Bounty Points (accumulated from doing RvR), Scales (items dropped off of monsters in certain zones and easily farmable), and Glass (again, a form of currency dropped off mobs in the game's Trial of Atlantis area). All the items purchased through these forms of currency are tradeable, so you yourself do not have to have BP's to wear the BP items, just know someone who has a lot of BP's and is willing to buy it for you and trade/give it to you.
From a mixture of player crafted and BP/scale/glass items, even a newer player can get a template that is comparable to the best in the game. The only super top notch items that are not purchaseable are Master Level 10 items (currently the best in the game) and some periodic limited time drops (such as Halloween quest hats and the Medal of Honor quests).
The community is not what it once was b/c you no longer need the community to succeed. Almost everything can be done by yourself, so large scale PvE raids are very rare. RvR is still very active on all 3 sides, and no side has any clear dominance over the other two. In fact dominance usually changes over the course of the day as population shifts I guess from realms that have higher European populations to the realm that has the highest US primetime population (Alb).
Oh, and as for the expansions, there is only one game now, so if you go to the herald and download the game, that is it. You will be patching for a long time bringing you up to date, but there will not be anything else you need to purchase except the monthly fee. As for the original post, I doubt there was any email that said "come back for a free week until we shut the servers down".