It looks like there are two problems going on. First, and this one's silly, you might not have accepted the XCode license agreement (See http://www.xensoft.com/?q=node/3).
To solve this issue, just try:
sudo xcodebuild -license # Press 'q' then type 'agree' to accept the license agreement Secondly, the version of MacPorts installed may still be verifying XCode's installation by looking for some directories that have been re-arranged in XCode 4.4. There's a patch for this that looks like it will roll out with MacPorts 2.1.2. Or now, if you're using your own Macports build using the trunk branch of the MacPorts svn repository. (See https://trac.macports.org/ticket/35150).