would the latest mac pro with an intel core 2 duo 2.8ghz 4gig of ram and NVIDIA GeForce 9400M + 9600M GT with 512MB. handle HD Video very well? id be using premiere pro.

Every Mac tower since the G5 handles HD editing perfectly. The question isn't can the tower handle it, it's how many streams of HD in the timeline can your system playback in realtime. That, unfortunately, is not a simple answer and has everything to do with fast RAID setups and proper system configuration. You'l need to read up on system configurations and the various types of setups - which vary greatly depending on budget and intended purpose.

We've been using Premiere Pro CS4 on a MacBook Pro laptop ever since it's release with no issues handling HD footage.

You mean Mac Book Pro I think....

all I can tell you is that my 2008 model (i.e. a lower spec MBP) handles XDCAM-EX3 footage superbly well with Final Cut Pro, don't know about Premier Pro though.

Dave, You mean Mac Book Pro I think....

all I can tell you is that my 2008 model (i.e. a lower spec MBP) handles XDCAM-EX3 footage superbly well with Final Cut Pro, don't know about Premier Pro though.

Yep, my tired eyes didn't catch the technical layout above...

And to bolster Andy's response, we've been cutting HD footage (DVCPRO and HDV) on even older laptops going back to the G4 with no problems. Again, it's all about proper setup, in fact back then I posted a thorough review on how to capture P2 footage directly to FCP (this was back when P2 cards were impossible to get, circa 2005).

Premiere Pro CS4 is actually just a tad faster at similar operations than FCP so now worries about using Production Premium on any MacBook Pro.

What's HD video to you? HDV, DVCPROHD, ProRes HQ, HDCAM, 10-bit uncompressed. etc. A new Mac Pro can edit any of those but if you hit the high data rates of say uncompressed, then you need to start rolling in more RAM, faster hard drives, etc.

Noah