Very simple style that only hides the video durations for the moment. The idea is to avoid spoilers. It's limited because only the thumbnails are affected but now you can safely browse channels !

The next step ? Tweak the wicked Flash player ! Until then my advice is to avoid the duration displayed in the bottom left corner and quickly switch to fullscreen. Press "Space" to play or pause the video instead of using your mouse and wait for the bar to automatically hide. Voilà !