The Google Base Blog announced that Google Base data feeds now support a new YouTube attribute that allows you to define if the product has a video demo on YouTube.

The example given is a product search for Nikon d90. If you scroll down, you will see videos from YouTube:

To add this to your product data feeds, you need to add the YouTube attribute:

Google does not promise that even if you do add this attribute to your data feeds that the videos will show, but it can’t hurt.

This feature has been on many folks waiting list for a while now.

Forum discussion at Google Base Help.