Apple has today announced that as of January 31, 2011 the Xserve will no longer be available for purchase. In a PDF detailing the change [PDF] Apple outlines that it will continue to honour Xserve warranties and extended support programs.
Apple also offers two server solutions, the first is the Mac mini server which Apple says has been the companys "most popular server system". Apple has also introduced the Mac Pro server which is said to "deliver performance and expandability equal to or surpassing Xserve, and offer an excellent server solution for customers looking for the highest levels of performance, storage, and expandability."