It is never too early to start pontificating on next year's Mac Pros and MacBidouille/Hardmac have today (tomorrow in France) put their cards on the table. They predict a burly monster of a Mac will come out of Cupertino in early 2010 sporting some pretty amazing specs. Here's their roster:
10GB Ethernet - I've been saying for awhile that this would be a great addition to both XServe and Mac Pro.
Support for 8 and 16 GB RAM modules (vs. 4 GB today) to push the maximum memory to 128 GB.
Support for video cards like GeForce Fermi or Radeon HD 5870
The CPU will be Hexacore (6) CPU 32nm Gulftown Processor with 12 MB of shared cache