you haven't payed attention to AMD
why not
performance wise, AMDs actually perform better and cost less than Intel processors.
Here's why... clock speed is only 1 piece of the puzzle when it comes to processor performance. while it is true that AthlonXPs and Athlon64s run at lower clock speeds than Pentium4s, they are still faster than pentium4s.
AMDs make more efficient use of each clock cycle than P4s do, which is why it does not have to run as fast to perform well. also, the L2 cache in an AMD processor does not duplicate the L1 cache like Intels do, so they L2 cache does not have to be as big either.
Just to use as an example, an AMD Athlon64 3800+ runs at 2.4GHz but performs as well as a 3.8GHz Pentium4... get it??
For years AMD has held the CPU performance crown, Intel has not been able to make a faster processor than AMD in years. however the soon to be released Conroe core Pentium4 is supposed to outperform any processor on the market today, so it would appear that Intel may finally take the performance crown back from AMD after years of second place (we'll have to wait to see how long it takes AMD to win it back, I have faith in them
)
To sum it all up, the socket939 Athlon64 series are the best CPUs you can buy right now, so if you're going to build tomorow then get a s939 AMD64. if you can wait a few more months then you may want to wait for a conroe