I just had my MacBook for a few weeks and now the battery already died. It won't power up without its power-adapter at all, and once it is running OS X just tells me "No batteries available".
Seems I am not the only one.
Guess I got to go to the Apple Store tomorrow and ask for a quick replacement. I just hope I don't have to wait weeks for a silly new battery. First revision Apple products... what did ya expect.
sigh,
muesli