I'm not sure which provide the links in Lenny, but I know none of them do it on the N900. I'd bet it's part of the setup script for one or more of the packages, probably the package(s) that provides the connectivity. (eg. if there's a cups-smb-backend.deb, it probably provides the link for smb). It could also be part of the dbconf package, which I think is a placeholder package for the N900, since it revolved around configuring an actual Debian system, which is not quite how Maemo is laid out.

All said though, running the link statement above does cause the dropdown in the web interface to populate, where a clean package install doesn't. The fact that that's all it takes to get this working is amazing. (Well, that and all the work you and BruceL have put into porting it!)

Thanks again to everyone who's worked on it for getting cups up and running! Only a few things use it right now, but I see this being as integral to the N900 in the future as fMMS has become for the phone side, if not more so. As more app developers learn that cups exists and add the minimal support needed to print via cups, the N900 is going to really start replacing my laptop.