HardMac:

based on what we know, the final decision hasn’t been made yet, so we believe that there is still a little chance of seeing Apple’s course of action changing. […] To go even further, but we are not there yet, it would be Mac OS X Server that could be discontinued. There will be a server version of Mac OS X Lion, but it might be the last Mac OS X server update.

They also report that Apple may discontinue Xsan and Final Cut Server too.