It would be nice to have something like RubyGems system have - you can subscribe on packages and get your own rss feed (https://rubygems.org/dashboard.atom?api_key=key_here) with package updates.

I think, this is related to #30109, because it also proposes "subscribe for updates" mechanism, but it uses email instead of RSS. It would be nice to have both and be able to decide, which one you want to use. It would be even nicer to be able to subscribe to most packages updates as RSS and get update notifications for some chosen (lets say, critical) package updates by email.