Once the API allows for write access, maybe something can be created to expand and replace (if approved by the user) shortened URLs, when a post includes one? Like Jeff wrote:
if you see a shortened link that has no reason to be shortened, then un-shorten it
For tr.im URLs, for which the creators have announced they would like to shut down the API and redirection service by the end of 2010, it might even be nice to do some batch processing. It's only 39 links though.