I have ordered my i7 as a back up to my Mac Pro. When it arrives it'll be mostly be for watching TV, doing presentations and the like so 4GB should be fine for now.
I am truly impressed at what you get for these machines. I practically paid the same for just one of my 30" ACD's. Crazy. I effectively get a 27" LED display (despite the Glassy display) AS WELL AS the following thrown in: i7 CPU with hyper-threading (that beats the base quad Mac Pros), 1TB HD, FW800, Gigabit ethernet, SD card, 4 USB ports, Mini-display port, Audio In AND Out, wireless keyboard, new Magic Mouse etc etc - Incredible.
It should be very interesting to see what comes out in Q1 in the new year for the Mac Pro, MacBook Pro and MacBook Air ranges.
These new iMacs have levelled and set a new bar; and redefined expectations.
I don't normally buy 'consumer' grade Macs, but the new i5/i7 iMacs are closer to Pro level specs. And at the prices they are going for I think they are a complete bargain.
I don't normally gush like this, but I think have done a triple plus on these machines