Download Videos LEGALLY from YouTube

I think YouTube recently introduced this new feature where a user can legally download certain videos. Right below the position bar, you will see "Download" link> Click it and you will be taken to Google Checkout window. This is what YouTube has to say for new downloading feature in their Youtube Support Page :

In general, downloading videos from YouTube is not supported. We are however currently testing an option with a small group of partners, giving them the ability to permit downloading of their videos downloads for free or for a small fee paid through Google Checkout. For more information, please visit our Blog and the following Help Center entry about partner video downloads.

http://www.youtube.com/watch?v=9KuwJXMQUdc

update**: Not all the videos have this feature. Actually, this is the only video that has this feature.