CHANGES

FIXED Lion users: if Safari Omnibar doesn't launch when restarting your system, please re-install Safari Omnibar from the installer. It now bundles a patched version of SIMBL fixing this issue.
IMPROVED Handling of unknown URL scheme by asking system if another app registered it (Fix: #71, #58)

NEW
Replace the location field content (current page URL) by the last performed search to help search refining when:
- Invoking Edit > Find Google... (Cmd-Opt-F) ;
- Invoking File > Open Location... (Cmd-L) but only if current URL is still the search engine result page of last performed search
NOTE: This is the first non chrome or firefox like behavior added to Safari omnibar. Let me know if you like or hate it.
FIXED Fix post install script bug when username contains spaces
FIXED Force javascript:, feed: and man: shemes as URL
FIXED Escape '&' and '+' characters so they can be used safely in the search query

NEW Make Edit > Find > Search Google... to init a search in omnibar with the default search provider (fix #38)
NEW Make the location field's text selected on File > Open Location... (Cmd-L), ready to replace its content
NEW Add special keyword "?" to force a search with the default search engine
FIXED Crash when doing empty search with a custom provider
FIXED Installer postinstall error
FIXED Beachball when performing single word search with slow resolver (fix #33)
FIXED file:/// URLs goes to Google (fix #32)
FIXED Single word search detected as URL when system domain search setup with wildcarded domain (fix #36)
IMPROVED Rewrote URLs vs search engine query detection algorithm

NEW Automatic plugin upgrades using Sparkle
NEW Search provider editor (right click on location field text -> Edit Omnibar Search Providers...)
FIXED Trim leading space from search terms when using custom search engine
FIXED Allow access to about:* urls
IMPROVED Better detection of URLs vs search engine queries in location bar

NEW Custom search engines by keyword (eg: "w " to search on Wikipedia)
NEW WebKit nightly builds support
FIXED Detect scheme://domain-with-no-dot and domain-with-no-dot:port as URLs in order to fix localhost issues