bDule provides Twitter access with groups, multiple accounts and the ability to view the accounts in one aggregated column or multiple columns per account. Twitter search is also available including the ability to save searches. The Facebook integration pulls in your full feed with the ability to post status updates directly to Facebook from within bDule. Also included is the option to post comments on your friend's content and "like" it.
bDule is built using Microsoft's .net platform and is only available to computers running Windows. My hope is that they will eventually build a Mac version which I think will help the company to grow virally. It seems like these types of applications grow faster when they are platform agnostic.
From my discussions with Facebook and Twitter power users, these new desktop applications appear to be the only way to use the service. For the record I use the .com websites and don't have any desktop application currently installed.
bDule faces stiff competition from valley-darlings Seesmic and Tweetdeck.