You guys should consider the relevance of each proposal and the number of votes it has since users aren't tied to vote one proposal alone.

Solution #1 though should be prioritized since it's also reported as a bug/enhancement and has another 40 or more votes in bugzilla.

Solution #4 is good too since I always asked myself, why refresh the repos since I've done this 2 minutes ago - simply remove the installed apps from the list - If the user thinks something new has shown up he can refresh by himself.

I also liked Solution #5 but we actually have an app for that don't we? App watch? - something similar anyway.

For the rest... I suggest more votes, or separating them in another brainstorm, to start working on this one.