Another way, almost as good, quite a bit less....
I too lusted after a Quad i7/SSD after seeing the awesome videos of boot times, app launch, etc.
I fully support anyone spending their money however they want (I have my own toys 🙂 ) but the price of these systems was high for me.
I wanted to end up with a quad i7, SSD and HD so I could run the system on the SSD and still have 1 or 2 TB HD for stuff.
I looked at the BTO imac prices, yikes!
I looked at buying a stock imac and adding the SSD. But if your starting imac did not have an apple SSD, this is not for the faint of heart (it can be done but do your research first).
In the end I took a different approach, and bought last year's model on ebay. So I have the quad 2.93 i7/256 SSD/2TB HD/8GB RAM, paid $2,035 on ebay for a machine that is 8 months old and still under warranty.
Compared to today's model, I don't have Sandy Bridge, I have 2.93 vs 3.4GHz, and I don't have Thunderbolt.
On the other hand, I saved about $1,000.
Worth considering IMHO. If you have the money and this is what you want, by all means get the new one. Just wanted to point out there are other options to consider.
PS I LOVE the SSD! Far and away the fastest computer of any kind I have ever used. Forget benchmarks, the user experience is night and day compared to a system on a traditional HD.
Cheers!