I don't think having a "like" rating is a good idea, as there is no real relation one could base an evaulation on: There is not necessarily a relation between the number of likes and the actual quality of an app, but rather the popularity, e.g. a flawed port of an emulator many people will like (like dreamcast) will probably have more likes than a "perfect" one for a less popular system (like SchneiderCPC).
With the long standing problem of minimal rating participation, I'm inclined, to join those that recommenond to remove them completly.
ptitsebs post remineded me of the biggest problem I have with ratings in the repo independent of how it actually is executed: What exactly should I rate ?
Only the technical part or also the "experience/satisfaction" I get from using it ? And there is also the problem that if I reduce my evaluation to only technical aspects, there is still the possibilty that one dev seems "offended" because I am not able to "see" what effort he put hin > Imagine port A gets a five star rating (or whatever else rating there may be) because the software just works as the it was a rather easy thing to port it to the Pandora. Port B only gets four stars, because it lacks certain aspects of convenience (like no fullscreen possible) to the end user, but the dev already spent several days getting this on the Pandora (reasons could be messy code, x86 based optimizations, etc).
A spontaneous idea was to implement some kind of "curation" system (that not necessarily needs to replace a rating system):
Every repo user has the ability to tag a repo entry with the tag "recommended", but needs to enter a small text to complete the process. Other users are able to see which users have recommended a particular entry and are also able to see some kind of user profile that contains a list of all entries that were recommended by the user. In an ideal case the user could also outline his gaming/pandora usage interest in an additional box, so people can get a rough idea what they can expect from a certain curator. This could of course be combined with other mechanics, to create more attention, like "following" a curator and getting notified if he recommends an entry or creating a list of "top" curators (but the term "top" should need some clarification beforehand).
This does not alleviate all problems (like the one I described in the first paragraph) but at least it gives the user another parameter to base its decisions on.