I just activated Cata after having not played WoW in 1.5 years. WoW has changed over the past years and it is very easy to catch up to everyone. There are welfare (easy) epics everywhere and you can get RICH by getting mining/herbing and selling mats off as you level. Low level mats sell for up to 20g a stack easy since people have so much money and nothing to spend it on aside from power leveling their alts professions. As far as MMOs go, WoW is the most forgiving to new players and allows people to catch up to the curve quickly. New players can have unlimited gold by simply leveling gathering professions, gear is plentiful, if you have friends, they can powerlevel you through instances, etc...
I see from your other game choices you like a wide variety of games. Might I recommend picking up Fallout: New Vegas? It's a very fun game if you like RPGs. You can download mods that turn it more into a FPS type game. For example, I downloaded a mod that increased your damage outside of VATS and made headshots a 1 hit kill with most weapons.
Battlefield Bad Company 2 is an AWESOME FPS game. IMO it's best out at the moment. CoD is probably a little better if you like just constant action, but if you prefer tactical side of gameplay, BFBC2 is tops.