Look for the script vmware2libvirt, it worked wonderfully for me.
One thing I haven't gotten my head around and I don't know precisely where the problem lies.
On Ubuntu 8.04 (and perhaps earlier) I could open Places/Networks/Windows Networks and see the local workgroup and open each machine to see, and open, their shares. With F9 I open the Windows Networks icon and it finds nothing underneath to open. This may or may not be relevant to what I am about to say.
With a VMWare vm I can open other shares on Windows boxes on the network. As it happens they are in the same workgroup. I don't know ifi it could span workgroups. But I have a NAS unit where the external directories show up as shares in a winxp system.
Under KVM those same WinXP images (converted via vmware2libvirt) actually run markedly faster than they do under VMWare Workstation, which is way buggy and crashes under F9 (worked fine under Ubuntu 8.04 albeit slow). But in the KVM vms of those same WinXP images I can not open shares (or even see them). As I mentioned I don't know if that is related to F9 not being able to either.
But google vmware2libvirt, it will make short work of you vmware vmx files. The only thing is you need to have a single extent vmdk image file, as opposed to n number of 2GB extents.