Similar to what Splashcast once did with its Facebook application (which has since been discontinued), Ffwd gives you the option to import a specific video feed, be it your favorites or all videos you've uploaded, and turn it into a content channel. This means you can have it automatically post to your Facebook wall every time you upload a new clip. You cannot, however, select individual clips to be sent to your Feed. A small workaround is to set up to post your favorites, then bookmark the clips back on the video service you're using.
Where this comes in handy is for content providers who want to re-syndicate content they're putting on these sites, onto Facebook without having to worry about the setup or upkeep. In turn, users get to watch the videos right on the page without leaving the site.
Right now this app only works with YouTube and Brightcove, so if you've got your videos elsewhere you're out of luck. The company says more services will be added shortly, along with the option to add any video stream by its RSS feed. Until it gets those extra services, this application is somewhat limited. In comparison I'm using FriendFeed which has been set up to post to my Facebook wall any time I upload or bookmark a video on about five different sites. I can also manage what it's posting from both FriendFeed and Facebook.
In the meantime, if you're just interested in doing this for just YouTube there are several other pre-existing Facebook apps that can post your latest uploads or favorites to your wall.