Well, we've been working to come up with a suitable solution for the past year or so, but it's incredibly hard due to the way the infrastructure works and the limitations that are imposed. Sadly we don't have a product to offer as yet. We've run into multiple issues and due to the fact that every single streaming application that you can use with Livestream and other competing services seems to demand un-encoded video it's really hard to actually get HD video onto a notebook.
The only affordable Express card I'm aware of that is available in retail with component video input is this product from Avermedia http://www.avermedia-usa.com//AVerTV...d=490&device=4
however, it requires a high-end notebook to do realtime H.264 encoding at HD resolution, but it should be fine for lower resolutions on a reasonably average notebook these days, although the card only works with Windows.
Hope this is of some help and hopefully we should have some working hardware in the not to distant future that will make everyone's life easier when it comes to live streaming video.