Live streaming with Twitter and RSS information
You may want to look into Camtwiststudio for the mac. I work with Desert Bus for Hope doing a weeklong stream as well and we use it for just the sort of thing you're talking about.

Camtwist has built-in plugins for both Twitter and RSS, and can leverage quartz composer to make more complicated overlays.

It outputs a video feed for other Mac OS X applications to see it like a QuickTime video source, so you can use wireless or Flash Media Live encoder to do the actual compression and streaming.