There's another search mode on search.cpan.org, which normally would always point to the most recent version of a module: http://search.cpan.org/search?module=Tcl::Tk.

For this particular case, it returns (for now) an intermediate search results page. I would think that's what you want anyway. But for most modules, it'll jump directly into the module's docs, for example for CGI: http://search.cpan.org/search?module=CGI

I wish Perlmonks had a cpan shortcut to that kind of search: it'll only find exact matches, but it (usually) jumps straight into the docs. I would think that for references people make to modules make in posts, this would be a most excellent link.