Intel is working on a point-to-point processor interconnect called QuickPath, which is a
competitor to AMD's HyperTransport.
AMD will support HyperTransport 3.0 with its next-generation sockets (AM2+ and F+).
HyperTransport 3.0 lets you split the links in half, so you can have 8 links total (and HT3.0
links can run twice as fast as HT2.0 links, so the half-width links should have good
throughput). I assume this will enable a fully-connected (diameter of 1) eight-socket server.