I had trouble installing Air, got that solved, then found Widget Browser and Adobe Help would seem to start, but never show a window, and they'd "quit unexpectedly" when quitting.
Noted that, when logging into a different account, the applications worked fine.
This was solved by deleting the Macromedia folder from ~/Library/Preferences under the troublesome account, then relaunching the Widget Browser and Adobe Help applications. Relaunching recreated the Macromedia folder with some new subfolders and files, including ~/Library/Preferences/Macromedia/Flash Player/www.macromedia.com/bin/airappinstaller/airappinstaller, among others.
Mac OS X 10.6.8
Adobe Air 2 build 230
Widget Browser 2