Current version: 2.1.1
Version 2.1.1 released.
This is primarily a release targeted at tracking down some nagging problems; but it includes the ability to disable error messages for those suffering from errors even when the plugin is correctly shortening and posting your status updates.
2.0.0
- Fixed bug introduced in WordPress 2.9 where logged in users could only edit their own profiles and associated issues.
- Fixed bug which caused #url# to repeatedly be added to the end of tweet texts on reactivation or upgrade.
- Fixed bug which generated shortener API error messages when no URL shortener was used.
- Fixed bug which prevented display of URL on edit screen if no URL shortener was used.
- Added Spanish translation courtesy of David Gil Pérez
- Made so many language changes that aforementioned translation is now terribly out of date, as are all others…
- Added ability to restrict posting to certain categories.
- Added option to dynamically generate Google Analytics campaign identifier by category, post title, author, or post id.
- Added option to configure plugin to use other services using the Twitter-compatible API.
- Added support for YOURLS installations as your URL shortener. (Either local or remote.)
- Redesigned administrative interface.
- Removed use of Snoopy and alternate HTTP request methods.
- Discontinued support for WordPress versions below version 2.7.
- Major revisions to support checks.
- Version jumped to 2.0.0

Update to my last comment: I installed this plugin last night on my blog and it’s working just the way I want. I had hard time with Tweet Me and had left configuring it.
Joe, I tried to use Tweet me, and it’s just not working for my blog. I dont know where it’s stuck but I would like to give this a try and see if it works for me.