I'm currently running a GTS 250 (1GB) on a e8400 (3.0GHz Core 2 Duo) both at factory settings. I'm planning on upgrading my GPU and CPU (likely to a i5-2500k) in the next few months but won't be doing it in one fell swoop. Will I see better performance running with a new GPU (6850?) on the e8400 (maybe with a slight OC) or the GTS 250 on a i5 CPU? I'm mainly playing BF3 and LOTRO, obviously at not too high of settings.
I would say go for the GPU upgrade... always better to have more graphics and besided the cpu you are using is still ok for most games. i see you choose a radeon, did you have a look at Nvidia aswell? you can get the ASUS GTX550 Ti DC top for slightly cheaper, and then you have cuda + Physx, better image quality.
Not that you need the same answer 3 times buuut GPU and a little overclock will work wonders I had a e8500 at 3.8 ghz and that would still be a good performer today... GPU up to you really but I would wait for the radeon full line flesh out and for Nvidia to show their stuff at CES to pick something. Also once those come out last gen stuff will be cheaper.