technically yes, but not fully supported yet. If you install one it's usuable via windows. As a gaming add-on Mac OS support will lag for this (you can install one on a Mac and boot into Windows, but that doesn't really count.) I know zero windows users that have one.
There is very little being sold new today that won't run vista
Not in it's full mode. Most of the el-cheapo systems don't have a Direct X 9 supported video or 512MB of memory. If you want to use Aero in the Premium product you need 1GB of memory. The system you priced below won't support Aero.
and when most of the computer useing world is used to useing your current systems messing with what the user can do risks loseing customers.
I have no idea what this means. Apple has been pretty good about allowing users to leverage their existing software as they move forward, and they've done it through much larger changes than Microsoft has ever attempted. The interface of Vista is as large a change as OS X was to Mac OS 9 users. So was XP interface different than Win95/Win2000 interface.
Apple's major changes:
Motoroloa 68xxxx processors to PPC => no loss of software, some loss in old software execution speed.
OS 9 => OS X. No loss of software, no loss in speed. Most software companies charge to upgrade to latest version.
PPC => Intel chips. no loss of software, some loss of execution speed for old software (not as much as expected). Most software companies provide free upgrade to native software.
Depends on the end you're looking at. As I said, el-cheapo end will be more expensive. I wasn't clear, but the cost competitive side is on the more expensive end.
Apple: $3198
* Two 2.66GHz Dual-Core Intel Xeon
* 1GB (2 x 512MB)
* 250GB 7200-rpm Serial ATA 3Gb/s
* NVIDIA GeForce 7300 GT 256MB (single-link DVI/dual-link DVI)
* Apple Cinema Display (20" flat panel)
* One 16x SuperDrive
* Apple Keyboard and Mighty Mouse - U.S. English
* Mac OS X - U.S. English
Dell: $3260
* Intel® Core™2 Extreme QX6700 (8MB L2 Cache,2.66GHz,1066 FSB)
* Genuine Windows® XP Media Center 2005 Edition with re-installation CD * 1GB Dual Channel DDR2 SDRAM at 667MHz - 2 DIMMs
* 250GB Serial ATA 3Gb/s Hard Drive (7200RPM)
* Single Drive: 16X CD/DVD burner (DVD+/-RW)
* 20 inch UltraSharp™ 2007WFP Widescreen Digital Flat Panel
* 256MB nVidia GeForce 7900 GS
Heck for the price difference throw in Windows XP Home for the Mac and you can use that physics card.