Support for kudos, accepted solutions, mentions, subscriptions has already been added for realtime notifications. I believe the support was added from 13.10 release.
Sorry I got my wires crossed as I was looking at this thread by amanda_optly http://community.lithium.com/t5/Developers-Discussion/Adding-Analytics-Events-to-Kudos/td-p/182559 about hooking in analytics on these very same actions. For a second I thought Lithium had expanded the event subscriptions and not told anyone :) I agree having a push style event model instead of polling would be great.
We've looked at using the notifications API to create a "my friends activity" component however it hasn't moved much more than a basic concept.
Sounds interesting.
We are currently looking into real-time notifications and how to use them in a third-party application using the API or some websocket-like service we could subscribe to. Unfortunatelly, there is very little (or no) documentation about this stuff..
