Ah well, random people with a web-cam and too much time...........what can you do?
But anyways...I would like a Public Beta, but I completely understand why they wouldn't; for these reasons...
1. It's really a little bit too late for a Public Beta this close to release date. If people were to find a huge error, fixing it would delay the release date (AND GOD FORBID THAT!!!!)
2. There's no need. Beta's are mainly for finding errors with the programming. Most people (incliding the guy in the vid) just want one simply because they are impatient.
3. Less than 10% of the people who play a Public Beta would provide "Constructive" feedback on the game.
So IW would rather keep Modern Warfare 2 in a closed Beta for now, because they trust their testers to provide constructive, accurate feedback. This way they can make the best possible game they can and still release it on their promised 11|10|09 date!