Microsoft's David Dennis, has explained to Cnet that "the first-week figures show that at least 2 million Xbox Live users have logged into Facebook..."Not only that but "half a million Last.fm accounts were created in the first 24 hours of availability" this lead to 120 million minutes of music being streamed. As for Twitter, no figures but, "tweets (have come from) from nearly every market where we have Xbox Live."
We expect Sony's video figures to hit very soon.
Source: Cnet