Seesmic Desktop has just  been release, You should be able to update the current version on your desktop by restarting the application and it will update automatically or alternative download it from http://d.seesmic.com/seesmic/SeesmicDesktop-0.2.a ir
New Improvements

Add your Facebook account
Aggregated timelines for Twitter and Facebook accounts
Now supporting Twitgoo and Posterous in addition to Twitpic to share images on Twitter
Cleaner column look and feel
Optimized use of space to display more tweets
More tooltips on buttons
Improved error handling (especially for connection problems)
Improved pre-selection of “SHARED as” account to reply or retweet from
Remembering your preferred image …