The Extreme Edition is Intel's "numbers" chip. It was made to win a numbers war with AMD. They priced them so high because their yield is extremely low on them and they really don't want people to buy these chips in heavy numbers.
Basically, the AMD 64bit Dual-Cores out perform the higher-priced Intel chips in every benchmark, Video Editing used to be one section where AMD won out - but even that is no more. I won't even get into the fact that the Intel chips are disgusting when it comes to power usage and heat output compared to the AMDs...
The AMD 64bit Dual-Core Opterons win
again , and
again , and
again , and
again , and
again
At the end of the day though, it is your money and your system - will be blazing fast no matter what.