If you go to my launchpad home page you can now subscribe to an Atom feed about all the branches that I am involved with (whether that is branches that I am reviewing, coding on, etc.) This just went live a few minutes ago, and Brad did a great job coding it up this month.
You can also subscribe to branch feeds for a project or project suite, something I think that is super interesting for an open source project leader, they can easily watch the various activity of people who are pushing up branches of their code.
It's very enjoyable working on a system that I use myself, even when people tell me I'm pushing the limits of the way the system was intended to be used :)