I've thought about this too, but I decided it's not worth it, for the same reasons.
Due to an unfortunate incident involving my stupidity and the high level of account thefts that are going on right now, I don't have my account with my Level 80 Human Mage anymore. So since I'm not ready to quit yet, now I'm in the process of rebuilding and I'm trying to speedlevel the classes that I had yet to level beyond 40 but which intrigued me (Priest and Druid).
I also agree that the endgame content isn't quite all its cracked up to be. Heroics were fun at first, but after awhile they just got repetitive. PvP is an option, but it seems that everyone that does PvP is just so GOOD...I would get raped in just about every one-on-one BG situation/duel. Plus, I don't really take the Alliance vs Horde "war" very seriously because I have characters on both sides, like many things about both, and part of me kinda wishes the two factions would just come to a truce. I guess I'm just a casual player at heart.
Jen, which server are your current characters on? My main characters are on Dawnbringer & Thunderhorn for Alliance and Horde respectively and I have friends that I already play with on those servers, but i also have a Tauren Shaman on Sentinels. I plan on rolling a Worgen Warlock & Goblin Rogue

devil

when Cataclysm launches...maybe some of us could check out the new content together then?