If you’re hosting your own video content and need robust streaming that’s cross platform and html5 friendly then Adobe Media Server with good encoding presets and a robust back-end works well.
Here’s an article that details a project I was involved in a while ago. It serves as a good reference on the approach we took to make it work. The actual web application is live and hosted by Web Learning Solutions for the Minnesota Humanities Center.
I’m Saying Adios to F4V. By Jan Ozer