Hello. I don't see that anyone has replied to your post. And I too have been wondering about what WebKit version is embedded within Adobe AIR. I know there is a link to the WebKit port specifically for Adobe AIR under Webkit.org:
http://trac.webkit.org/wiki/ApolloWebKit (this is the post to WebKit.org by Adobe Systems)
But I haven't tried this yet. I'm sure there is something within the Adobe AIR documentation or language reference that specifies level of WebKit support.