Adding Jeff since he created the RSS source Jira (it needs polling).
I do have a patch which polls and consumes RSS feeds. However, I feel we can delegate this to hubs of pubsubhubbub http://code.google.com/p/pubsubhubbub/ and just consume the feeds pushed to it.
I would like to know more about the vision of Flume regarding - "real-time web feeds and near-realtime analysis".
hubs would definitely become hotspots, if all kinds of webhooks ping it. We can use Flume to aggregate data from different hubs (some can be hosted like superfeedr, other can be local receiving pings from yammer-like internal clients). There are interesting ideas that stem from this aggregation and near real-time analysis
There is huge community on webhooks, pubsubhubbub (based on webhooks), HTML5 WebSockets and Comet. Each of them push "data" real-time and turning the web into "Evented web"
Pubsubhubbub is based on Webhooks. We can even make a flume node to consume events from directly Webhooks if needed.
Git uses webhooks to push commit feeds: http://help.github.com/post-receive-hooks/
HTML5 WebSockets and Comet