On a related topic, how does one best balance the number of cores v. clock speed?
I'll let Ken handle the AMD vs. intel thing since I'm not up the latest details there.
In cores vs clock speed, additional cores will only be of use to software that is designed to take advantage of it. Some tasks are better parallelized (i.e. split into chunks that can be run simultaneously on mulitple cores) than others.
Since computing power has been moving, in earnest, in a multi-core direction for about 3 years (on the consumer end of things, anyway), more an more developers are (or should be) taking this into account when they write their software.
Ideally, you should know if the software you'll be running is written to take advantage of multi-cores before you make the call on which chip to get. Since we live in the real world, I'd say put a slightly higher priority on the clock speed at this point.
