An article on Anand Tech says the patch does fix these issues.
Microsoft has published knowledge base article 940105 on the matter, and with it has finalized a patch to reduce the high virtual address space usage of games under Vista. From this and our own developer sources, we can piece together the problem that was causing the high virtual address space issues under Vista.

You can get the hotfix by online request @ Microsoft.With performance numbers literally the same with and without the hotfix, we can safely say that there is not a performance penalty for using this hotfix.
VNet is also hosting this hotfix:
Download: KB940105 [32-bit only]
View: Full Article @ Anand Tech

