Looks like sourceforge and ironically M$ has an extremely useful site for HTML5:
Some really great topics where you can learn things like:
How to use SVG files.
How to embed video streams.
How to Optimize
Device Orientation between different devices.
How to make Gradients
I think I am most excited about the use of SVG files. A lot of my graphics are exported raster images from inkscape. Using the SVG files would be a MAJOR time saver, and the graphics would be far superior to their raster offsprings. I would love to do this in C2 without 3rd party plugins.
Looking forward to learning about video too.