I would buy it today...but I have a few sticking points.
1. Sata III. The current iMac ship with Sata III controllers but have installed SATA II drives. To make matters worse, the SSD that it ships with is a dog of a Toshiba that was the same that shipped with the 2010 model. There are rumors that SATA III and Sandy Bridge do not play well together (altho I hear that is being corrected on Sandy Bridge) and maybe Apple choose to ship these slower drives knowing that it would create less of a support headache for them. At the same time however, I am not going to buy last years SATA technology when SATA III is at our door step. Some would say, just go to OWC and have them install the latest if that is important... it's a consideration, but I live in Asia and so I would have to install them myself. I have installed drives and memory in Mac Pros, mini, MBPs, etc... but opening a brand new iMac doesn't look fun and I'm not ready to go that route unless I have to...and that might be fun! I'm looking for a SATA III drives in my iMac working properly with either Sandy Bridge or Ivy Bridge.
2. Cores. I would like to see a 6 core processor...but I would be happy with a 4 core i7
3. Form Factor. I love the form factor, but the drives should be more accessible for replacement for whatever reason and Apple should use standard cables.
4. SSD (digress from issue 1). The current iMac ships with a dog of a SSD, the Toshiba...same as the 2010 iMac as a stated above. While I would go with the Samsung drive that is in my MBA (umm, wrong form factor I know), I would prefer Apple to get with it and start to provide SSDs that actually perform. Apple is supposed to be the best of the best ... yet the SSDs are the worst of the worst with the highest possible price. The latest SATA III SSDs are 500+ r/w - rock on OWC. Yet, Apple is shipping 200 r/w Samsungs or Toshibas that are dog slow. It's kinda insulting but to most people who buy... they will never know...but shame on Apple. Obviously, the TRIM issue is out there... and sand force based SSDs don't need TRIM support in the OS. So we probably won't see a sand force based SSD in a Mac, but man...it would be beautiful if that was a BTO option. Till then, APple is backing away from it's relationships with Samsung, so who knows what kind of POS SSD is on the horizon. If Apple slacks...ill just buy from OWC and install drives myself...
Thats about it... so we are in day 145... average is 240 days for the last 4 refreshes or so... so within 3 to 4 months we should see a refresh (yes, this might just be a Sandy Bridge speed bump update as Intel just released new SB chips and the IB has been delayed). This line is a big money maker for Apple so they are refreshing often. So January or February at the latest. Maybe Ivy Bridge in October 2012. The other scenario is that IB is released in Q1 12 and Apple postpones and we don't see new iMacs till April 2012. Either way, within 6 months we will have new iMacs to choose from.
To stay calm, I went ahead and bought a Mac Mini i7 today, ordered 8GB of ram from OWC and I will use that as my desktop computer until the iMac is released. So maybe if you are on the fence, you can do the same. The Mac Mini won't be refresh for a while, so you could always sell it on ebay for 80% of what you paid for it (loose 200 bucks) or turn it into a server or re-purpose in a million ways
I'm looking forward to my iMac, but i'm digging in and waiting....the current iMac is a blazing tweener...