I think WoW needs an "endurance" dungeon. Basically there are unlimited waves, and every 10 waves there's a boss. Each boss drops one tier better loot than the previous one (so that all players regardless of gear would be interested in this dungeon), but the item level caps when it reaches the highest item level available to players at that time. Of course the wave difficulty increases after each boss, and especially at high item levels it should increase dramatically. If i had to make a wotlk equivalent, 1st boss would drop 187s, 2nd boss 200s etc... then the 7th boss (which should be VERY hard) should drop 264s, 8th boss should be literally impossible and drop 277s, and all bosses after that also drop 277s. This would also give hard competition for top guilds to get world firsts (imagine at frontpage: Paragon beats Endurance Dungeon Wave 11+Boss - World First!). There is the also the possibility of an Endurance raid, instead of an instance. Blizzard has shown great creativity for Cataclysm, if they decided to work on such an idea i believe it could have great results.