Apple announced back in November that they were planning on killing the XServe line of rack-mounted servers at the end of January, and this is the day: after today, you won't be able to purchase an Apple XServe through Apple, or register an AppleCare Protection Plan against an XServe purchased from some other retailer. Apple has said they'll continue to support XServe owners and people with existing service plans for the duration of those agreements. 

Apple's server line was never a flagship part of its business, but the company did enjoy some success with the servers as a way to get their foot in the door in large enterprises, colleges and universities, and the federal government. 

Apple has said they’re replacing the XServe with the Mac Pro desktop that we all know and love, just running Snow Leopard Server instead of the desktop version of Mac OS X. Alternatively, people looking for OS X servers can look to the new Mac Mini with Snow Leopard Server bundle. Even so, the death of the XServe signals something many analysts never thought would ever happen: Apple retreating from a market they didn’t find particularly beneficial to their bottom line.