Pottermore? What could it be?

So a lot of people are thinking Pottermore is an MMORPG... Personally I hope it isn't. I'm an avid gamer, but I hate MMO games. Could it be the encyclopaedia? I wouldn't call an encyclopaedia a book. I'd call it an encyclopaedia. And apparantly Jo's people are adamant that it isn't a book (unless they're throwing us off the scent.) What do you guys think?