The numbering system that AMD has is what used to be roughly equivilent to an Intel cpu. Not too long ago intel changed over to a more elaborate numbering system which no one knew what it meant. That meant that an AMD 2400+ was equivilent to an old Pentium 4 Northwood chip(My old one).
Just because the AMD chips have a lower clock speed does not mean they are not as good. They just can do more at that clock speed and still be the same as an intel one. If you'll remember on
last week's RSBANDBUpdate! we talked about new chips that were coming out from Intel. These chips no longer use the old numbering system.
However there was a problem with the Prescott's which were what was used in making the old extreme edition, they had many heat problems.
Now with Intel's Core 2 Extreme and Core 2 Duo out soon, AMD still holds an advantage as their dual cores are more affordable. Some benchmarks have suggested that intel dual cores perform better at office tasks while AMD dual cores don't perform as well but are still good for office and gaming related tasks.
There is no question AMD is better for gaming. I have a X2 3800+ in this system and it is great. Even though it only clocks at 2.0Ghz. (I got it up to 2.2Ghz without problems

)
In the end there are still relatively equivlent.