When you share a video on the site, or even just watch one, the service can optionally blast your activity to your Twitter followers. There's also a new bookmarklet that makes it easy to share any video link on Twitter without actually going to the Ffwd site itself.
I suppose if I find a video I really want to share, on either Ffwd or elsewhere on the Web, it's cool that I can now easily Twitter that out to my followers. And it is interesting to think about how Twitter could become, for some people, an activity stream of what their friends are watching online.
Call me crazy, but I'm not going to have the site send out a Twitter every time I watch a video. (It won't happen on my feed anyway, since I don't hang out on Ffwd.) Mercifully, it appears that Ffwd posts are not quite flooding Twitter yet.
The service reminds me a bit of Twitpic, a picture-posting site I have used. The big difference is that I mostly use Twitpic to post pictures I have taken myself, not those that I discover on the Web (it helps that Twitpic is integrated into Twitter clients Twhirl and Twitterific). If I wanted to send out quick self-shot videos to my followers, I'd look at Ustream, which has Twitter integration, or Seesmic, which has cool video conversation features.