Digitimes says Microsoft's plans for producing and upgraded CPU for the Xbox 360 have been pushed back until the middle of 2007. What does this mean to you?
Well, upgrading the CPU from 90nm to 65nm means the processor will run less hot, and will require less power and cooling. This means less fans, less noise, and less power consumption from the console as a whole.
Should you wait until '07 to buy your 360? Only if you're really picky about how much noise the 360 makes in comparison to the PS3 or the Wii. Most of the noise in the earlier units was due to the DVD drive, which was lessened when Microsoft switched manufacturers on those as well. Otherwise feel free to buy a 360 now. It won't be that huge a difference.
65nm Xbox 360 CPUs delayed until mid-2007 [Digitimes]