My guess - the iMac is going to be repositioned as a high-end product in the top tier along with the Mac Pro. The Mac Mini is probably going to go away, essentially replaced by the AppleTV and iPhone. And a new entry level Mac will be introduced at the sub-$1000 price point.
Mac Pro $2499+
iMac $1499-$2499
New Mac $999-$1499
That would be a very stupid move by them. Apple is not going to gain market share by increasing prices on their already successful products. Instead if anything they would want to bring in more people by offering a new line to fill the gap between the Mac mini and the iMac.