Upgrading to a new GPU

Your resolution is not very demanding, i doubt that you even noticed a low perfomarnce occured while playing, even games like BF3 will run smoothly at ultra setting on that resolution, so it would be wise if you wait for the new kepler architecture GTX 660, then you will notice a huge difference, the 560 ti is great but it won't be a good deal since the 660 is almost out, also you will need to change your PSU because the extreme power plus series from cooler master is the lower efficiency on the market and won't deliver proper power to the 560 ti, so it will be a waste, just wait for 660 and change the PSU at that time, Believe me the 660 totally worth it......

But anyway take my advice, as long as your GPU doing the job, don't upgrade, because you won't stop, you will be upgrading each single month....