Honestly the getting viewers issue seems to be fairly straightforward and was solved by traditional broadcast a long time ago. When they wanted people to tune into a live broadcast they _scheduled it at a particular time_ then marketed this time.
To be clear, I completely agree that TV studios figured out how to get people to watch live content very well. But I disagree that that's applicable to potentially millions of simultaneous individual broadcasters.
I'm not sure why its not applicable, please explain. In fact I think Justin.tv's role could/should be one of facilitating this process? Why not a Justin.tv Guide?
The biggest downside of live video content on the web (and this can't be resolved) is that one thing the web brings is a global reach, and you're not going to be able to adequately serve a global audience with live video.
As to the second, that could be a great problem for Justin TV to solve ;-)
I think the problem is either they're not serious enough about their content or that unscripted, live shows are hard to lock down to a single length every week.
When online shows are scripted, filmed, and edited down to exactly 22 minutes, then scheduling will get much better.