Compared to the paladin and warlock 60 mount quests in terms of effort involved, the druid's epic flight form quest series is rather easy.
For starters, there will always be the necessary herbs on auction for the quest that requires them, and everything else you need is in Moonglade or Outland. Compared the travel pallies and warlocks have to do, travel for the druid epic flight quest is relatively little.
Also, doing heroic Sethekk Halls at 80 will be like running reg Ramparts at 70. Getting to Outland from Azeroth, assuming no mage ports or warlock summons, is fast and easy compared to getting to Feralas or Eastern Plaguelands. There are a lot of quests involved in the druid epic flight form quest, but they're all pretty easy and all of them except heroic Sethekk and perhaps one of the statue fights (depending on spec) are easily soloable. (As feral spec, I had to call in a friend to heal me for the avatar that was weak to spells).
For a level 80 group (even to include one 70 druid) to clear to Anzu's room and do the fight would be fast and easy.
Lastly, for at least the first few months of WotLK, most of the people playing in the 70-80 range are going to be people who already have their key for heroic Sethekk. There are always going to be people questing out of Terrokar/Bone Wastes whenever they level a new toon. Outland dungeons (compared to many/all of their Azeroth counterparts) are fast, tidy runs with a decent group, and the loot isn't going to become fully obsolete with WotLK People are still going to be running Outland dungeons for xp/quests and gear as they level new toons, which means that if they didn't hit Honored from the quests in Bone Wastes and Terrokar, they're likely to hit it with an extra SL run or two. Heroic keys for Auchindoun dungeons aren't exactly going to be in short supply.
The main thing is that the key to get anything group oriented done "easily" is to have a decent guild or a decent group of friends in the game. The anti-social types or the types of folks who insist on keeping themselves in crappy guilds will always have trouble with group content for personal rewards.