This is awesome. One bit of feedback: It'd be cool to have some fixed area on the screen where you are showing the current chord (in a big font), while the video is playing. In the Super Mario example:
http://www.soundslice.com/yt/Y6ti5f-LHp4/
It's tough for me to follow the tab while it's scrolling rapidly by... so I'd like to see a big A7 / B / etc. on the top right corner of the screen, so I can follow along with my guitar.