WOW. I'm like right there with you buddy!
I had a E4600 OCed to 3.0 and a GTX 260 (Currently still using until i get my new thermal pads from the GTX 480 i bought off a friend) and that ran pretty good for me on most games (Minus ones that needs DX11. I did use that on Crysis 3 with a 660 i borrowed. It LAGGED even on lowest settings.
Now i got a Q6600 OC'ed to 2.6 and it runs even better. Thinking of getting a Q9550 for a 100 bucks which is pretty much the Max you can get with a Socket 775.
I just got titan fall beta and it runs great on my 260 and Q660. If you want to run like 3 screens and everything max graphics then yea get a new PC. If you just do basic 1 screen stuff you can get a cheap video card upgrade and CPU for like 200-300. Otherwise if you can spend more would be better off getting at least a New Mobo, ram, cpu. Can keep the video card for a while and then upgrade that later.