I've noticed that I'm getting annoyed by the fact that when PK updates the list of packages in the repos in the background (which is fine), a notification icon appears.

This is annoying because:

 + I don't care about this event: there's nothing I can do with it, no
   interaction, nothing, nothing. Did I say nothing? :-)

 + it creates a "movement" in the notification area since the icon appears and
   then disappears. This is distracting.

So I really think it should just show no icon at all.