It would be wonderful to be able to post #HashTags (like Twitter) that were linkable searches to "Activity Stream" posts.
Also it would be ideal to have the feature like StatusNet that allows you to post to a group directly from the Activity Stream much like you have in the drop-down menu but with perhaps the exclamation point. So if you had a group called BuddyPress you could post to it from the "Activity Stream" like this:
There is a #NewRelease of !BuddyPress today.
