I currently own an i5-2300 along with a pretty cheap m-ATX board, H67MA-e35 from MSI. Reliable though.
I was checking current CPU benchmarks and was shocked at how the new i7-3770k compares giving over double the score on benchmarks. Now, the age old question - would I really see a difference between the 3770k from my 2300 in normal and gaming use or should I wait until the next generation of CPU's? My GPU is a 560 ti 448 and I plan on getting a 2560x1440 monitor soon.
If the answer is I would see a substantial difference, I'm currently looking into this board for Ivy bridge.