Well, I suppose someone ought to give a not-CPAN point of view. For me, the app-on-CPAN thing should be pretty much dictated by extensibility of the software in question. For example, CGI::KWiki was designed to be quite simple but also extensible.
IMO, if the app you've written is something which could feasibly work as the underpinning of something else, then I would put it up. But, in this instance I don't think that's the case. But I'm mostly against the apps-on-CPAN thing anyway: I would much prefer to see a separate directory of apps written in Perl. The namespace problem you outline is one of the reasons; that doesn't affect just where you put the files but also where one might look to find something. Unless apps are placed somewhere suitable in the hierarchy, it would be difficult to see how the search would work: Freshmeat, for example, has categories and all sorts of things, CPAN doesn't.