I am planning a new build for the beginning of May.
I set my mind om the i5-2500k. However, the Ivy Bridge i5-3570k just came out and its roughly $40 more expensive that the i5-2500k here in Canada.
I am not a huge gamer and I dont think I would require PCI 3.0 support. I am planning not to do an upgrade for 4 years. As such, although on a budget, I would like to have a system which will allow me a decent computer experience (i.e. not having a lag when browisng the internet or not having enough power to run Windows 9 if it will come out by then). My Intel Core 2 Duo E4300 was purchased 5 yrs ago, and it sill runs good.
So in short, will bying an Ivy Bridge i5-3570k be a better decision if my next upgrade will only be in 2016? Is the Sandy Bridge i5-2500k just as "futureproof" as the i5-3570k and the release of the Haswell and Skylake architecture will make them both "outdated" around the same time? In which case it doesn't matter whether one had a Sandy Bridge or an Ivy Bridge CPU.
Its the socket they use that determines their "future-proofness" and since they both use socket 1155 they have the same expiration date. Its my opinion that the i5-2500k will serve you better than the IB as it can clock higher to make up for the slight performance gain the IB brings to the table.
edit - just make sure you get an IB capable motherbd so that in 3 years when you might want a slight upgrade you can run a (hopefully) much higher clocked IB or newer.