If the iBooks weren't going to be updated until october then we would have seen at least the video card increased to 64MB if nothing else (along with eMacs and iMacs.) The fact that they didn't get this indicates to me that they will be updated at/around WWDC. If they had received a small bump and then were updated again at WWDC, then there would have been lots of complaints from buyers who thought they were cheated by Apple.