(As discussed - briefly - here)
I think that starring is going to become very important for high-volume rooms, but maybe it needs another icon. Starring is too much like voting - too many people are using stars to mean "I like it, it's funny" rather than "this is important".
Maybe 'pin'? or 'landmark'? 'Salient point'?
And it could/should also be used for marking not just individual posts, but (for example) the beginning of an interesting/important discussion.
When you return to a busy room after a long absence, you basically have the choice between:
- reading from where you left off (
load to my last messagelink at top of page)
- jumping in 'cold'
- scrolling up an arbitrary distance for a look
- 'reading the stars' (haha)
And ideally, the stars would be a reliable guide to what's going on.
EDIT Mark just pointed out that there is also a 'catch up' tab in the user profile... very neat.