IMHO
The chances of VMware releasing a fix "soon" for today's version of Fusion running on a developer preview of an operating system that isn't listed as supported is probably somewhere between 0 and none. VMware didn't get access to ML before almost eveyone else did. If past experience is any guide, any "fixes" will probably at or after the time that ML actually ships and they announce Fusion support for ML.
Developer previews are just that - to give developers a chance to look at the new technologies and begin tooling for support of the OS and its new features.
They're buggy and given that Fusion has to reach into areas of the OS mere mortal applications never tread (e.g kernel drivers) it's no surprise that at this stage of the game there are issues.