Think I'm buying a new Mac Pro but....

First, I'm a PC guy and I'm just getting into editing High Def movies (AVCHD). I was thinking about buying a new Intel i-7 PC but thought that if I could get faster rendering etc... out of a Mac I'd buy a Mac. So... my question is what would be a faster computer for video editing, etc... I'm not going to game. I will use the computer mostly for video/photo and general web surfing, word processing, etc...

What do you guys think between these two systems. I am really a newbie on Mac's but everyone is steering me in their direction... I want speed.

Mac Pro with dual 2.26 Nehalem processors, 6 Gb DDR3 1066 RAM, 1 TB hard drive @7200 rpm with an ATI Radeon 4870 512 mb video card....

OR

PC with single Intel i-7 Extreme Processor at 3.2ghz, 12 GB DDR3-1600 RAM, 1TB hard drive @7200 rpm with a Nvidia GTX 295 1792mb video card.

Any suggestions would be really helpful. P.S. I know this is not a apples to apples comparison but don't know if 2 processors at 2.26 is slower/faster than one at 3.2ghz and more/faster RAM.

Get the Mac!

(sorry, all this technical talk has me thrown for a loop)

I do have a friend though who edits videos for Spike TV and he's used a Mac since forever.