My big hope with a redesigned iMac is that they make the hard drive accessible. I think its a scam that you practically have to get a service person to replace a hard drive on the current iMacs. Ideally I would love to see an entry level tower that is halfway between the mini and the pro, but I highly doubt that will happen. Apple seems to be stuck in the smaller is better market for anything except the tank of a MacPro and the XServe.
I for one would rather have a chin on an iMac than have to be an Apple certified technician if I want to upgrade my hard drive without voiding the warranty. Its like the tiny iPod shuffles, they lost one of their best features, the USB port so they could be half the size. Like the shuffle wasn't small enough as it is. Smaller isn't always better.