Yes, I think that VMware Fusion should be geared also towards technology enthusiasts (like myself and others): for example, virtualising OS X 10.6 Server gives the possibility to run old PPC apps (with Rosetta), something that one might enjoy from time to time (for example, AppleWorks 6, Adobe CS2 apps, and so on).
Thus, it would be a good thing if also legacy OSes - such as OS X 10.6 Server - were better supported.
Well, let's hope for some improvements in the future...
BTW, there is also another audio option for Snow Leopard Server VMs: the VoodooHDA project, which is a driver for Intel HD Audio and so doesn't require modifying the .vmx (anyway, the last time I tried it, it didn't work; but it could have improved, in the meantime).