Today, Seesmic Desktop appears to be the first to market with full Twitter Lists support built right in. Select users have been using the new build for a few days now, and Seesmic plans to rollout the new release to TeamSeesmic members early this week.
Seesmic Desktop's Lists support is as good as, if not better than, one could home for after such a quick turnaround. Not only do your existing created lists now appear in the left-hand column, but you can also add users to your lists and create new lists from within the app.
One thing we'd love to see is the ability to convert our existing Seesmic user lists into official Twitter Lists, but we can probably expect features like this to be added in the near future. As Loic Le Meur tells us via email, "This is a preview release we worked on as soon as Twitter made the API available given the success of lists, we will add more features soon. We wanted our users to be able to display and add people to lists immediately."
While being first to release Twitter Lists support is certainly a big win for Seesmic, we expect to see many more applications, including TweetDeck, to follow suit in the very near future.