Im not sure if anyone's noticed or written about this yet but the Twitter option in feedburner [webmasterworld.com] has gone awol. In fact the entire "socialize" option link now appears missing.
The service is still active(for now), you can manually navigate to the socialize page by typing the address in your navigation bar. old address: feedburner.google.com/fb/a/socialize?id=YOURIDHERE
What I liked about the service was that it automatically used Google's shortening service for links which comes with analytics. At this point the service is still active though unreachable if you don't know the address so it may be taken offline, eventually, or perhaps it will just stop accepting NEW connections but will not change existing connections, or?
Perhaps Google simply decided to stop promoting twitter altogether after their fallout over tweet indexing. Who knows.