8 core is really intense... but if you've got the money I say splurge ?

Personally if it was my $$, I'd say save the money and get the 2.66. Put the extra money aside and use it to replace the machine with a newer Mac Pro sooner than you would have with the 8 core. Buying the highest end machine isn't the wisest choice as the industry moves so fast now.

If you were doing intense photoshop work, or major number crunching where time was of the essence, by all means get the 8 core. Its worth it for professionals who can use the processing power to their advantage and speed up their workflow.

I dunno how serious you are for video editing, but the 2.66 or 3.0 quad core should be more than enough for your needs...

Either way, you can't really go wrong... Check out barefeats.com for speed comparisons & bar charts... They also have pretty good bang for buck analysis...