This typifies a philosophy which is very alien to many people. Your motherboard limits you on many fronts from using current technology, be it Sata3, USB3, faster DDR3, etc... Even if it doesn't, early implementations are usually buggy, slow, and not 100& compatible.
If you're on your fourth cpu since AM2+ came out (late 2007) you've upgraded four times in three years or under. This is a rate most people find unreasonable unless you're a student with lots of time and not worrying about running up huge cc debts.
Why not just do a clean build every couple years and stay current on everything, and keeping your old build together for a hand-me-down... though I'm guessing many of your friends and relatives already have hand-me-downs from you.
Your philosophy is very alien around here (E Europe) To spend $400 for just a new mobo and CPU? Maybe if we rob a bank or something. And in here with VAT and stuff it's not $400 it's $500+. I've build entire rigs for cheaper. Nope, we do it this way. Cheap futureproof mobo ($70-80) and cheap CPU. When we get our hands on some more $$$, sell old CPU and get a new one. And so on. I, for one, don't sell them, I have a trickle down economy amongst my family/friends.
AMD is very popular for it's cheap triple cores and quads - who cares about the synthetic benchmarks like "3DSMAX, Cinebench and whatnot? or about features like USB3.0/SATA3. My DDR2 mobo hasn't seen the last of it's CPUs yet, probably it will be a 6 core.
Anyway, for gaming (we don't skimp on the GPU) the result is a rig almost as fast in gaming as a Sandy Bridge with the same video card - for a smaller price and the possibility of cheap CPU upgrades without changing the platform.
The expansion of the PC market happens mostly in the developing countries (mainly Asia) so AMD might be toast in the first world but has a great future in many other places as long as they keep producing cheap dual cores and quads and offer socket stability (Intel renounced that, the 1156 lasted for 1 year and a half).
LE Also Intel simply doesn't want to cut the prices for the old models, take a look at the 775 socket quads.