My budget: $1500
My needs: ~60fps with Ultra settings on BF3 & FC3 with 1080p resolution
Hopes: to be able to get about this performance on upcoming FPS games for 2-4 years by SLI'ing and OC'ing my CPU..
Your on the right track for future proofing your rig, with occasional upgrades rather than a massive initial investment.
Two points I can see that might be an issue later.
That 660Ti has a 192bit memory bus, right now that might not be a large issue, but who knows how games will develop later on. Might want to pick the HD7950, which has a 384bit memory bus and more VRAM.
One way to future proof a rig is to get an overkill case. That way you can support larger motherboards, custom water loops, more drives/bays and such without having to change the case.
Also, don't get the motherboard recommended by pcpartpicker, microcenter usually has a deal in store if you buy for example an amd processor you get 40 off a motherboard, which leaves more cash for other upgrades.