Using an estimated guess...i'd say about 46-48 wide....probably closer to 46 for the woods racers. I'd LOVE to see them offer options with the width myself...this will accomodate xc/mx riders alot more than is being offered currently!
I believe they have the specs up now and the official width is 48". Which is pretty nice, because all you need to do is get 4+1 offset rims and you can get back down to 46" up front and then get a adjustable axle that goes narrower than stock and you should be set to hit an XC course.
I lied it's 46. For some reason I thought it was 48, which would have been really nice.