Seesmic Desktop: The Sincerest Form Of Flattery
I was a guest at Seesmic’s launch of a new desktop clients for Twitter (and other streaming social tools) last night. There is a lot to like about the new Seesmic Desktop (the old Twhirl name is being deadended along with that product), but the most lasting impression is that the new mode of use is largely based on the very successful competitor, Tweetdeck.

Seesmic Desktop, originally uploaded by Stowe Boyd.
The application is based on Adobe Air, as are most other competitors in this space, nowadays.
The multicolumn user experience of Tweetdeck has been replayed in the new Seesmic offering, and much of what made Twhirl tick has been dropped.
Columns can be manipulated individually, and moved from side to side, in the now-standard Tweetdeck fashion.
I haven’t used the client for any length of time, and many of its projected features — like Facebook support, Seesmic video support, and so on — are not yet implemented, so in essence what we have to evaluate is a minimal feature set of what is planned, which boils down to being a multicolumn Twitter client with URL shortening (from bit.ly, is.gd, and digg), ‘userlists’ (or groups), and Twitpic integration.
Seesmic has dedicated some real estate on the left margin to navigation, and there doesn’t seem to be a way to close this or convert to smaller icons.
So in conclusion: Seesmic has taken its cue for the new Desktop from Tweetdeck, aside from a few stylistic tweaks. It seems to be a sleek and usable Twitter client, but is no breakthrough. Looks like a horse race, though.
[Full disclosure: I am an advisor to Betaworks, an investor in Tweetdeck.]