I have set this up, but have been unable to get it to work. I think the main reason is because Windows XP can share a postscript printer as a Unix postscript printer, whereas that is not the case for Windows ME and down. I should think, if one had Samba installed, that we could get something like this to work:
Print Center->Samba->Shared Fake Postscript Printer->HP
but I haven't found any helpful information regarding this. The closest I have seen is that the person working on the Samba Server Config Tool says it's possible, but it would be a pain.