Dell has finally released some details about their new, four-socket R900 server that will support the new Xeon 7300 series quad-core CPU. This new box has 32 DIMM slots, so it can hold up to 128GB of RAM. The fastest CPU available for it is the Quad-Core Intel Xeon X7350, which runs at 2.93GHz, with a 1066MHz front side bus and 8MB of L2 cache per CPU. The Xeon 7300 series are based on the newer Core architecture instead of the old Net Burst architecture that the Xeon 7100 series used. The full specifications for the Intel 7000 sequence processors are shown here. You can buy one of these processors at NewEgg for $2550.00
This server will be a substantial upgrade from something like a Dell PowerEdge 6800 in terms of performance, but it probably will not be that much more expensive than a 6800. It will definitely be a great box for running SQL Server 2005 or 2008.