To be fair, a number of us have always dabbled in other games - I used to play Everquest2 as an antidote to WOW, and more recently have delved into the depths of Lord of the Rings Online - but the extent of the current experimentation hasn't been seen before. There's certainly a degree of burnout and disaffection - we've struggled to get even Kara or Magisters terrace runs up recently - but it remains to be seen if this is a temporary disaffection (to be cured by WOTLK etc) or something more permanent. The people I play with in LOTRO have a history of switching games/servers unlike anything the Ravens have experienced, so this is new territory.
Whenever a new game appears there's a vocal bunch who say "WOW's time is over" but who come back after trying the new game for a while. Is this another such occasion, or will the combination of new game experience (novelty and new stuff to explore was an attraction to me in LOTRO) and WOW's seeming stagnation really bite into the player base?