The Future is Mobile

Brace yourselves ...

Stock Android browser may or may not support video, there are versions (2.2) with video support but no audio. Wat?
Browsers on mobile generally delegate codec support to the underlying OS
iOS on iPhones/iPod will pop video into the Quicktime player. On iPads it will not.
iOS and possibly Android will not allow you to play media simultaneously.
Mobile browsers generally ignore autoplay (requiring user initiated events to start playing)
Volume changes are usually ignored. The user is in charge damnit!
Opera Mini and other proxy browsers simply will not work.
Flash is rarely supported on mobile. (No fallbacks)
There are mobile browsers that we have never heard of. (Though most of them are based on WebKit).

Stats time