Same here.
-Skipped SB because my Phenom II felt fast enough at the time. The plan was to upgrade when IB came out.
-Skipped IB because it wasn't any faster than SB and overclocked worse
-Finally going to upgrade when Haswell comes out.
The difference between IB and Haswell is small, but the cumulative improvement when you skip several generations adds up. I guess that's the idea with Intel's tick-tock scheme... +10% with SB over Nehalem, +10% with IB, + another 10% with Haswell.
In the past, we had clock speed bumps, then more cores and IPC improvements. I think that era is over. Clock speeds have stagnated at 3.5 - 4 GHz. Core count has stagnated at 4-6 "real" cores. IPC improvements are limited to ~10%. This has been pretty obvious since around 2005 or so.
Keep in mind you'll be jumping up in supported instructions as well, I dare say we're going to see support for anything pre-Sandy dropped from support for games in the next year or two since anything bellow doesn't support stuff like AVX.