Great build. Would easily hold for a few more years, especially with the overcloackable CPU, which by the way I consider the best one available now if you count $/performance. But if you're looking for it to live long, why don't you get an extra 4GB of RAM. I know that 8 is plenty enough now, but RAM is currently cheap, so 4 more wouldn't set you back more than 30$.
Also, one more thing, I'm not an expert and I didn't do the math, but are you sure that you're power source is enough? You should consider that you have a very overcloack friendly CPU and account for it, and you should consider that you might upgrade your GPUs 2-3 years from now.
Also take special care when choosing the case and the cooling system.
And let me direct you to a very good website: http://www.anandtech.com/. Reading around there should help.