I can easily navigate through the new comments

(User Story, To be Fixed , Priority: Medium, Test Status: No automated tests yet , Reported By Justin du Coeur, )
Notifications
Summary: This should be something like CommYou or Wave -- I should just be able to keep hitting spacebar to navigate around the new information.
Ideally, this probably should include notifications other than comments, but think about order of events carefully. In particular, consider comprehensibility: I should go through all of the new information relating to a particular Thing together, in a reasonable order, before moving on to the next Thing. Once I finish all Things in this Space, I should go on to the next Space. (This may become several stories.)
The spacebar action should respect threading in a sensible way, going through all of the comments in a single thread before moving on to another, even if their timestamps are interleaved.