These are nice ideas. If you'd like to try them out and write some code then we infite you to he CPANHQ project which attempts to be an Open source rewrite of the CPAN module search/browser. It's still in early stages - but there is enough code to import some modules data and try out new ideas. The problem now is of bootstraping the system, we cannot assume we have all those additional socially gathered pieces of module data - we need to start with the currently available information, make something useful out of it and only after people find it compelling enough to switch from the two main cpan search engines - only then we can count on them adding new data.
in reply to Social CPAN : Finding the best and most popular modules