I’m in the same situation. A life long PC user (except for the old Com 64 days), I’m getting serious about film, sort of an offshot of my writing career.
I’ve worked with Pinnacle products with an HP for film editing and I’m extremly disappointed. I’m buying a 17” MacBook Pro with the upgrade 2.6GHz processer, a 4 GB, two SO-DIMM, a 200GB 7200-rpm hard drive and a second one at 250GB 5400-rpm and another HD 23” screen and my college kid’s picking up Final Cut Studio 2 for $499 with his school discount. The editing software usually runs about $1299.
The entire setup with be devoted to video and photos, nothing else. I’ll still use my PCs for word processing, spreadsheets, e-mails, etc (can’t quite cut the cord). I don’t want anything on the Mac that will interfer with the speed of it, especially with video editing.
In for a penny; in for a pound, especially when it’s not my money. I also promise not to turn into a Mac-Pr*ck, especially after I gave my brother-in-law so much crap when he moved to the Apple Darkside. I will not, however, buy an iPhone until I can replace my own battery and move to the carrier of my choice, despite the fact that I do find the b-i-l’s iPhone pretty cool.
Vista was the thing that made me make the move. 4 computers and 2 TIVOs on my home network and I STILL cannot get my new HP laptop with Vista to connect to it. An operating system should get easier to use with each upgrade, not turn into an new learning cycle of frustration.
I do small-time video editing on my dual-core iMac. I've found that the other applications don't interfere with it. The stuff you mentioned (except for maybe a huge spreadsheet) only causes occasional tiny blips in processor power to be taken away from my background rendering. Actually, running Activity Monitor itself to see this took more processor power. Even burning a DVD doesn't take much from it. And the system remains completely responsive to the other apps. This will be especially true when you have two separate processors with four cores each.
Don't forget, there's no registry on a Mac, no place that a bunch of applications stick their data and screw everything up. On a Mac you have some folders where applications stick their preferences and other stuff. I once tried to see what happens when I do a render and another conversion at the same time, and that wasn't a good idea. To simplify it, I'd say two jobs of an hour each separately were going to take three hours together. They were probably constantly poisoning each other's cache.