Twitter upgrade - embedding rich media or preparing to serve ads?

On Tuesday, Sept. 14, 2010, Twitter unveiled an upgrade to their website and service which now shows embedded video and photos in a dual-panel layout. While Twitter CEO Evan Williams says “78 percent of active users have used Twitter.com in the last 30 days.”, the power users mostly use 3rd party applications to manage their service and communicate across the twittershere (my personal favorite is cotweet)

The new updates are currently being rolled out slowly to all twitter users and I have to believe that this move must be in anticipation for serving ads. Twitter has discussed an ad model for creating revenue many times but so far has not implemented anything. This new dual-panel layout on their website is just screaming for advertising to fill up the space. I am sure it is only a matter of time.

What I am curious about is that the majority of tweets and usage of twitter is generally done by a very small minority of power users. And most power users are using 3rd party applications that bypass the twitter.com website and just hook into thier API. I don't know how they will be served the ads?

I am also curious about this quote from Williams: