NOTHING can touch the Intel Core 2s at the moment, in terms of raw power/speed clock-per-clock, and low heat output. This is the reason why Intel have delayed putting their new chips onto the market two months after they should have been, due to lack of competition from AMD.
And the Intel chips are extremely affordable.
Q6600 2.4GHz 1066FSB Core 2 Quad, 8MB L2 = £150.27
Intel DP35DP motherboard = £72.02
2 x 1GB DDR2 PC6400 (800MHz) Corsair RAM (with heatsink) = £33.65
Total = £256.
The Q6600 is highly overclockable, especially with other boards like the slightly more expensive Asus P5K.
The Core 2 Quad Q9450 will be released March 17th using the new 45nm fabrication process, 2.66GHz speed, 12MB L2, and SSE4 for any future programs that may support it. Price: £218. The Q9450 is what I'll be buying. Can be used on the same Intel DP35DP motherboard. See my thread in the Studio Equipment section of the forum if you're interested.