From the release notes:

New in version 2.1:

• A post or page can be deleted by swiping across its title in the Posts or Pages list
• Commenter email addresses are now visible
• The app now supports HTTP authentication for password-protected self-hosted blogs. Big thanks to Jeff Stieler for the patch.*
• Fix for link helper not working in mid-sentence
• Fix for lost content after changing status of post containing a <!--more--> tag
• Fix for visual glitch with buttons in Comments section
• Fix for problem recognizing valid URLs during set up

Get WordPress 2.1 from iTunes Store.