I'm most likely buying the low end model, Nehalem 2,8 ghz quad. Can't find any benchmarks on FCS but was curious what the speed difference is with the higher end models. (I'm coming from a G5 quad so compared to my current system I'll be flying anyway...) I believe only Compressor uses all the cores, right? I want to read up on it some more but don't know where to go for that information... For instance how much RAM I should buy. I think the consensus for FCS is anywhere between 4-10 GB but I have never read any official info on this.

It is suspected that the next iteration of FCP will be fully multiprocessor aware.

I PERSONALLY suggest 2GB of RAM for each processor core (a 12 core TO ME SHOULD HAVE 24GB as a minimum - your mileage may vary... GREATLY)

Barefeats.com is good for testing. I agree with Shaun that 2GB is minimum per core, so 8GB for your MP.

Thanks for your input. Just curious to know where you got your ´suspicions´ from, Shaun. Is it your suspicion, do you have insider info or is it merely to be expected? That's why I asked: where can I find this information? There is a whole bunch of assumptions, a lot of copying of opinions and (educated) guesswork but I'd like to read some verified information on these matters.
You also say you'd recommend 2gb per core. Based on what? Please lead me to this well of information...

I'm not trying to be demeaning in any way but I am really curious where to find hard facts on these matters.

I saw Barefeats tests the fastest Mac Pro against a previous model. I am actually more interested to see the difference between the 3 new models when running the FCS apps.