The new service, which should out by the first week of August, will allow users of TiVo Series3 and TiVo HD DVRs to stream the YouTube movie clips through your broadband connection. Unfortunately you will not be able to actually save the videos. You can however book mark them as a favorite.
As of right now, only about a third of TiVo users have the nessacary hardware boxes that are compaible with the new YouTube service. Apple has had a similar service for awhile now but, its no where near TiVo popularity.