Since they were not selling many, then they should have no issue certifying and licensing Mac OS X Server to run in VM enterprise environments (like VMWare vSphere) since it wouldn't be cannibalizing hardware sales of their own. That actually could turn out to be a much more lucrative market then XServers.
Anyone who thinks the new Mac Pro "Server" edition or using multiple mac mini's are a valid replacement in a enterprise environment clearly has never worked in, supported, or managed an enterprise environment.
This. Some of the ridiculous comments on this forum are from people with no experience from which to base said comments. If you have no experience of computing within an enterprise setting just keep quiet.