Automattic has released WordPress 2 for the iPhone OS, but not as an upgrade. Instead, users will need to download a secondary release of the app and eventually delete their original app.
According to the release notes, the update features
* A new, more efficient user interface that makes it faster to switch between comments, posts, and pages.
* Various user interface refinements and bug fixes
* New Comments interface, with Gravatars and the author URL shown in the comment list
* Passwords are now stored in the keychain
* Posts are now automatically saved and restored if network connection is lost during publishing
* Added persistence, so the app re-opens in the blog you last used
* Added an interface for manually entering the XMLRPC endpoint for non-standard setups
* Fixed rotation-related visual glitches
* Fixed errors where malformed XML prevented access to XMLRPC endpoint
* Fixed edge case where local drafts were sometimes not saved
* Fixed the order of photos so that they’re displayed in the order they’re uploaded