As per http://code.google.com/p/twitter-api/issues/detail?id=173 we'll be changing the /account/verify_credentials method to return the representation of the authenticated user. Because some applications depend on the contents of this response, we're delaying this change until December 10th, 2008.
Please update your applications to verify by response code, not by the response body for this method. If you get a 200 back, you're verified. If you get a 401 back, you're not. If you can't ship an update in 8 days, please let us know and we'll push the date out further. -- Alex Payne - API Lead, Twitter, Inc. http://twitter.com/al3x