I guess that would depend on what you're looking for from this game. Obviously, alot has changed since you were here last and catching up will keep you busy for some time. The game has become more casual friendly and altaholic friendly (heirloom gear).
I, among other long-timers, am still here, so that might tell you something.
Hey Shakks. Most of the core team is still around ... dunno if that's something to be proud or ashamed of. >.>
If you enjoy leveling (easy & fast, good quests, well designed zones, lore) then Wrath of the Lich King is for you.
If you enjoy PvP ... its in a horrible state right now stay away.
If you enjoy dungeoning, there's good news and bad news. Good news is there's some nice dungeons, they're quick, easy, and simple to get groups for now with LFG. The bad news is they are complete zerg-fests, little to no skill/strategy involved besides charge in and swing like crazy, even in heroic at this gear level.
If you like raiding their new 10-man model is perfect for us as a guild and for getting in pugs, with the exception that fewer lower-end raids are done server-wide. Gearing up is a breeze though if you put in the time to chain-run dungeons.
BTW, deathknight is impressively designed, taking the best of all classes and really making it work. They are very fun, though many still dropped them for their traditional "mains" after a while.