As a first time iMac buyer should I wait for Ivy Bridge?

[Zen0Jin]

And it brings a (drumroll) 20% increase in speed. That's it. Neat, but.....
I'd be more interested in what AMD can bring to the table at 28nm. I'd speculate on some 30-50% at the same power draw. Is it worth waiting a year for? Next lithographic shift is another 2 yrats down the line again, so no major change then until 2014.

The thing with Ivy Bridge is that it will be awesome for the Macbook Pros.

My iMac Sandy Bridge Core i7 hits 70C playing games, so Ivy Bridge is not needed.

20% improvement in performance? Of course, that happens every year. That should be expected actually, and very low by standards back in the day when of the Pentium when 300mhz year to year represented huge 30-50-100% increases in performance.