Typical, he "made up" his specs so you twisted yours too...
So MS finally decides to defend itself after years of Apple fud (which even you have to admit they were, to the point of being comically deluded) and instead of building up a solid rebuttal you write this? I mean, if you decided to pick a decidedly more expensive BUSINESS workstation to compete with a Mac Pro, why not go with the "boutique" level PCs? They are even more stupidly expensive PCs... However if you are a sensible person and actually look for price AND performance you would pick something like this:
Dell XPS 730x
PROCESSOR: Intel® Core™ i7-920 (2.66GHz, 8MB cache)
OPERATING SYSTEM: Windows Vista® Home Premium Service Pack 1 64-bit
OFFICE SOFTWARE: Microsoft® Office Home and Student 2007
VIDEO CARD: ATI Radeon HD 4850 512MB
MEMORY: 6GB Tri-Channel DDR3 at 1066MHZ (3x2GB DIMM)
HARD DRIVE: 640GB - SATA-II, 3GB/S, 7200RPM, 16MB Cache
OPTICAL DRIVE: Single Drive: Blu-ray Disc (BD) Combo
MONITOR: 21.5 inch Dell S2209W Full HD Widescreen Monitor
SOUND CARD: Sound Blaster X-Fi Titanium (2x TOS Link)
SPEAKERS: Dell A525 30 Watt 2.1 Speakers with Subwoofer
KEYBOARD: Dell USB Consumer Multimedia Keyboard
MOUSE: Premium Optical USB Mouse
FLOPPY & MEDIA READER: Dell 19-in-1 Media Card Reader with Bluetooth 2.0
EXPANSION PORTS: 8x USB2.0, 2x 1395a, 1x eSATA, 3x PCIe16, 2x PCIe1, 1x PCI
BAYS: 4x 5.25" optical bays, 4x 3.5" internal HDD bays, 2x 3.5" external flex bays (floppy/media reader)
SECURITY SOFTWARE: McAfee Security Center with anti-virus, anti-spyware, firewall, 15-months
Dell XPS 730x $2583
Oh wait, you say it is more expensive than your Mac? May I point out the better videocard, the 6GB of memory, Bluray drive, and included LCD monitor? Should I go on? And while there is a limited discount going on at Dell until June, this pricing and sale discounts are very typical across all vendors, except Apple that is.