There has been some steady work to improve the SMS Framework module and I think it would be valuable to outline some thoughts on a 1.0 release. As far as new features the biggest ones will be the ability to receive messages and support for the Muse gateway. There will also be major improvements to user interface and scalability for the SMS User module.
Issues I would like to see resolved for a 1.0 release:
http://drupal.org/node/255095 - many improvements to SMS User
http://drupal.org/node/258057 - text messages should include more descriptive message
http://drupal.org/node/254209 - receive text messages - Added
http://drupal.org/node/197338 - make sure sms_user info shows up on registration form
http://drupal.org/node/258044 - don't explicitly expose the number field or let admin decide
http://drupal.org/node/193821 - UI improvements to sms admin pages - Applied patch
I would like to keep the 1.0 release simple in that we won't be adding too much more functionality from what is already checked into CVS. After that we can look at a Drupal 6 release and other new features. Thoughts?
Update: All of the tickets for this release have been closed, take at look at the wiki page for the 1.1 release (including Drupal 6!).