I'm gonna chime in, I took a 4 month break from wow from being a casual player since 2006. Sometimes the daily grind does become ugh, and boring.
I did however take a break towards eve, free expansions, constant leveling. While I like some casual aspects of EVE, it gets very repetivive quick from solar system to solar system. But then again i do like just sitting back and making money off of investments.
WOW offers things new each round. New sights, new stories. However once you reach that magical cap, it becomes a grind after grind.
Thanks to Cataclysm, everything has changed so much i'm excited to roll a lvl 1 character all over again. However places like Outland and Northrend will be a "step backwards" repeat.
Torn between EVE and WOW. But for me, WOW runs at a faster pace with the ending catching up quick, where Eve can feel like it drags on and on and on as you do similar things over and over where the "raid" content is for players who've been there for 2 years and have billions in isk.
Price to Price.... Folks would spend $$$ on gaming PCs, about $50 a pop on the latest call of duty game, almost buy 1 $50 game a month or every 2 months, dish out $$ for consoles Pay for their $12 month Xbox LIve, Various itunes movies/TV rentals/downloads, Netflix...
I don't think a $15 WOW subscription is gonna break the bank