I'm looking to upgrade from my Athlon X2 @ 2.7GHz because I do more with the computer now than I did before - sometimes I'll play a game while my TV tuner is recording from my cable signal, and having more cores would help these multiple tasks run more smoothly.
I was waiting until the Clarkdale-based i5 launched, thinking it would be a quad-core that was more competitively priced against the Phenom II X4, but it looks like a Phenom II X4 is my only option to get more cores for less money.
The only good news coming out of this launch is that LGA1156 is not changing for the Clarkdale chips, so it looks to be the most future-proof platform to upgrade to, if one was so inclined. I'm personally going with a Phenom II since I can get one without changing motherboards. This is one of the more disappointing launches in the last year or so.