Guys, I think someone found a solution (unofficial one, but it seems to work).
here's the link, the samsung impression board Swervin Slurrin did an optimization trick, I tried it, the video's seem to work now. http://www.samsung-impression.org/browser/help-problem-w-youtube
"Hey everyone. I got youtube to play on my impression. It's a fix i read somewhere earlier.
I'm using opera. Make sure you have a youtube account created and you are logged in (if you are already logged into google then you should automatically be logged into youtube).
What you need to do is look on the bottom of of youtube mobile's site and click the help button. then scroll down the page and there is a section about optimization. Click optimise. Then lie on all the questions. (example: if you see an image lie and say no you dont see it)
On question 4 there is a button that says click here. Click that button. The next few questions lie and say you do see the videos.
Once you have finished optimising click on a video and hopefully you are lucky like me and it plays.
You can also go back to the optimization page and reset the settings if you screw up. I had to do this as I screwed up my first try."