MacRumors.com

Designed for the computational clusters and distributed applications, this Xserve configuration delivers high-density processing power ? without the server features you won?t need in a cluster enviroment ? for a price that?s easy to multiply across your deployment

Internetnews.com details some of the changes:

But unlike the original Xserve, which first shipped in July, 2002, the new server has only one hot-swappable 60GB hard drive, no graphics card, and no CD ROM.