Well, I'm 100% pleased with my 5770 @ 1920 x 1200. You 295 should be nearly twice as fast. There isn't a game out there I cannot play 100% maxed, including DX11. In Metro I have to keep ADoF off, but I can use some AA. Crysis no AA. All others maxed with the use of some AA. Not bad. Your card should fair quite a bit better including the use of AA... of course no DX11 but honestly you're not missing much... at least not yet.
I'd probably hold onto the 295 for now. Maybe wait till the 28nm parts are out. If you *need* to upgrade something, maybe put that several hundred towards a nice SSD. For that kinda' cash you can get one with decent capacity (120 to 160gigs likely). More than enough for your OS and some games.
Or compromise. How much RAM do you have? Why not a smaller SSD just for the os (like a 40 or 64Gig), and max your mobo out on RAM? With the GPU power you currently have I'd likely lean more towards the SSD + RAM, depending on how much RAM you have already.