Yeah even though the iMac has more horsepower per say, I like the display and computer separate as I have now.
Put in the Ivy Bridge processors, bump up the RAM, Intel HD 4000, and SSD. One model having the GeForce 640M LE would be nice as I said before. If not then let it be. Have the base model either remain at $599 or drop lower (without an SSD anyway if they get to $499) and if they don't make a discrete model, then drop the server to $799 or $899.