@dixon_jones, a well known and respected SEO, asked Google's JohnMu in a Google Webmaster Help thread why Google shows the old Twitter URL versus the new Twitter URL in the search results.
For example, my old Twitter URL is twitter.com/rustybrick but the new style for the Twitter URL is twitter.com/#!/rustybrick.
Yes, Twitter uses the new AJAX schema for the URLs. So why does Google show the old version without the #! in the URL?
JohnMu explained because Twitter redirects the #! to the old URL.
Google crawls AJAX URLs using the AJAX-crawling scheme which results in the URL looking like this instead http://twitter.com/?_escaped_fragment_=/rustybrick. When you look at what Twitter does when you access that URL, bots are redirects to the old URL.
#1 Server Response: http://twitter.com/?_escaped_fragment_=/rustybrick
HTTP/1.1 301 Moved Permanently
Date: Wed, 22 Jun 2011 12:46:47 GMT
Server: hi
Status: 301 Moved Permanently
X-Transaction: 1308746807-27933-10397
X-Frame-Options: SAMEORIGIN
Last-Modified: Wed, 22 Jun 2011 12:46:47 GMT
Location: http://twitter.com/rustybrick
Forum discussion at Google Webmaster Help.
