I love Premiere which will run on a PC or a Mac BUT I have always used a PC for editing.
I was going to stick with a new i7 PC computer but is this the right choice??
I don't want to start a PC\MAC war but desperately need some reasoned advice. Thanks.

Just a couple of observations:

1. MAC's are beautifully engineered
2. They look good
3. They work out of the box
4. They are very expensive
5. They offer very limited expansion capability
6. OS-X sucks with multi-threading
7. They offer far less forum support

Any other opinions from those that work with both PC and Mac and Premiere?

If you are willing to build your own machine (and are somewhat adventureous) you really don't have to choose. You can have both OS on a dual boot machine. That is what I did. SL and Windows 7 Pro can live happily in the same box. I am running FCP on the MAC side and Premiere Pro CS5 on the Windows side.

I've worked with CS5 on both, though I run Windows 7.

I found the Mac to be just fine, I don't know what the difference would be other than the display card options are a bit narrower and the media "structure" on the Mac is limited to only QT...so I do know that some types of AVIs do not load on Mac, whereas when you put QT on your windows machine, you have the filetypes supported by QT and Windows available...

I don't know how to really delineate them very much now that they are nearly the same machine... I guess it's OS preference.

Bill, are you using a nVidia card for acceleration in both OSes? Would be great to see a benchmark of the software on identical hardware.

Probably less expensive for you to go the "Hackintosh" route as Bill mentioned. You can have the best of both worlds and have better expansion capabilities than with a MacPro.

MacPro's, no doubt, are probably the best looking and built computers out there; but conversely also have more limitations than a Windows based machine.

Bill, are you using a nVidia card for acceleration in both OSes?

Yes. A GTX 285. Works just fine.