I've found quite a few postings that indicate that flash video (youtube or otherwise) will play in midori after installing these
sudo apt-get install gnash browser-plugin-gnash
However, all it does is just sit there thinking about playing video for as long as it can So far I think it's made it up to 3 hrs.
Current setup:
HDMI out, Mouse (but no keyboard in USB), Ethernet, Good Power supply (Samsung charger), wheezy 09 25 2013