You may not have picked up on this but over the course of my computing life time I have always gravitated to smaller and smaller footprint devices but have not wanted a whole lot of compromise when doing so. Apple products have consistently allowed me to do so in ways other companies have not allowed me to do. Do I care about the price - sure I do but more from an overall value perspective than a flat out lowest possible cost.
Apple had 1 Gig ethernet across their product line YEARS before it was in other products. 802.11x - same deal. Firewire - same. etc, etc. When it comes to hardware 2 years or so has been about the lifetime I expect before it makes more sense to upgrade the whole works for me. Maybe that will stay that way maybe not but here is the deal. For the stuff that I face off with I want it to be small, beautiful, fast, and pleasant to do business with hour after hour. I never have relished the thought of having a giant piece of equipment with all the associated crap, heat, noise, etc in my face. I rather that part of my computing universe out of sight and out of mind - preferably in a different, dark room somewhere I am not. I have successfully - in varying degrees been able to do this with Gig-e and 10 Gig-e with a bunch of custom built storage arrays, some switches, a bunch of software that I understand very well and other moving parts. Very soon I will not have to worry about the care and feeding of that stuff - or at least not have the overhead of assembling it and maintaining the software. That is why my Alien Technology SAN product is on hold for a while - ever since Apple adopted Thunderbolt IO ports in the MacBookPro's. This is a HUGE development that solves my appetite for huge fast storage that doesn't have to sit in a box right next to me.
Leaving out the DisplayPort stuff, Thunderbolt IO is pretty much PCI-express that can be carried over a wire somewhere else. This means that you can buy something that connects Thunderbolt to pretty much ANYTHING. This is a big deal and I am certain that vendors are going to be jumping on this in a big way sooner or later. Hence I want to wait until I see what the market is providing before I put time and energy into a complicated solution for the rest of you. If there are gaps I do plan on filling them but for now this is the direction I am going.
Now - why the iMac - why now. You can probably tell I am not a big fan of sitting next to a MacPro. It is a fantastic machine but give me back the space and flexibility in my work-area anytime. Along with the peace quiet. I tend to try to balance my equipment purchases for two things. The first is step functions. The newest sandy bridge i5/i7 processors are step functions not a minor bump of the same thing I have. Thunderbolt IO is a step function. The new Graphics subsystems with the amount of GDDR they support are step functions. All in all looking at the Apple line up - todays' MacBookPro and iMac's are a far better purchase in how much more you get relative to the previous gen vs the same comparison last year.
The second thing I try to do is get on the trailing edge/leading edge of price/performance. In this case RAM. 8Gig chips are new and big time expensive. 4Gig chips used to be that way but are now the best buy in terms of capacity vs price. Here is what I mean - 16Gigs of RAM for the new iMac using 4Gig chips costs $200. 16Gigs of RAM for the same machine using 8Gig chips cost a whopping - $1500. Which way do you think I am going?
You might say "But you will have to get 8Gig to go to 32gigs and if you go with the 8Gig you won't have to throw them away" - Who cares - If I wait for the 8Gig chips to come down in parity from a price/gig then I "throw away" $200 vis $1300 as compared to getting the same 16gig now using 8gig chips and upgrading later. The only way I would buy the highest capacity chips now is if I absolutely NEEDED 32Gig because the cost/gig is at such a premium.
The bottom line is that Now is one of the great times to buy a MacBookPro or iMac and get the most life out of it and the performance benefits along with dirt cheap 4 Gig chips as compared to say 12 months from now. Yea maybe they will be a little faster but not compared to todays iMacs vs last years.
No one knows what the future holds but based on a well established pattern of intel and Apple this looks like the sweet spot if you are looking for a new machine. Trust me - I have timed things like this for years with tech curves of all sorts and the iMac/MacBook of today will allow the next two or three revisions to be "who cares" for you until the next step function.
If all this techno mumble doesn't make sense use the "Holy Shit" rule of thumb. These new 2011 sandy bridge "consumer" machines are in the Holy Shit category compared to the last gen machines.