All it is is just remote debugging. A developer needs to have the ability to send information to the driver and get information back out of the driver. If they are sitting at a PC and they are hacking on the video card stuff then how are they able to see what is going on?
Right now I expect most developers use a seperate laptop with ssh or whatever. But that is not always possible to do and I suppose Vmware has had other reasons for doing what they want.
Linux has already very good network GUI support in the form of X Windows. X Windows is certainly vastly more capable, faster, and more useful then any other remote desktop feature that I have ever heard of.
And it can do lots of things that most people would simply think is not possible... stuff like this: