Intel showed the V8 Workstation, which features 8-Cores at the CES 2007.

The Intel V8 features Dual Quad-Core Intel Xeon processor X5355 CPUs running at 2.66GHz. Rob Enderle over at Digital Trends got a V8 from Intel and compared it to his AMD Quadzilla machine.

Quote:
"Having what amounts to unlimited headroom is damned nice. You don’t have to think about shutting stuff down if you want to do something else, you can multi-task everything, begin virus scans whenever you want, run video games (several at once if you want), watch TV or movies, and generally fry your brain, depending on your attention span and your tolerance level for distraction. "
Read the full V8 hands-on report.
On the Intel Capabilities forum you can find photos and the specifications of the Intel V8 Workstation, which has cost of around $4,500.

The key ingredients to build a V8 Workstation is the Intel Workstation Motherboard S5000XVN and of course two Quad Core CPUs.