Unless you want to wait for Haswell there would be no point in getting a new build now. The only thing I can see you doing is getting a newer video card.
EVGA 02G-P4-2678-KR GeForce GTX 670 FTW 2GB 256-bit GDDR5 PCI Express 3.0 x16 HDCP Ready SLI Support Video Card
If you take out the 460 and replace it with this GTX 670 then you would have atop quality gaming Pc.
EVGA 02G-P4-3684-KR GeForce GTX 680 FTW LE 2GB 256-bit GDDR5 PCI Express 3.0 x16 HDCP Ready SLI Support Video Card
There is also this card to consider and it would add to the performance of your Pc. What you can consider doing is to swap out the video card and keep the 460 so that when Haswell comes out and you decide to go for that cpu , you could put the 460 back in and put the newer card in your new build.
I would also not run your current cpu at that voltage as it will shorten the life of it , If you go over 1.38v for an extended period of time it shortens the life of the cpu and if you want to give it to a family member then you would want the cpu to last a while longer.