I have the i7 and its nice. Its pretty silent, although I run the fans at 2500 rpm to keep it cool (and it does stay very cool at that speed).
Its very fast, very very fast! Coming from a core2duo its crazy good. You could always hold off and wait for an update but the i7 is nice in itself.
Edit: I like the graphics card in it, I play WoW, TF2 and Left4Dead 2 and they all run great! WoW I can run at max native resolution and the more graphic intensive games I run at 1900x1200.