Qik.com (in addition to having a 3 letter domain) has had that functionality for a while. I've used it on my HTC Incredible to record video and have people watch, and also auto-upload to youtube.
Qik's iPhone broadcaster doesn't access the hardware video encoder, which unfortunately means that the output of their app is more like a slideshow than a real video stream.
We deliberately waited until the platform could support an app we would be proud of.
Yes and yes. We detect and use a hardware encoder on Android whenever one is present. It isn't always there, so we fall back to software encoding if we have to.
Not as well known as Justin.tv though.