Judging by the number of requests received for inclusion in TweetDeck, the marketplace for URL shortening services must be a blossoming one. Obviously spurred on by the growth of Twitter, where the act of URL shortening makes the most sense, the sheer volume means it is, sadly, unfeasible to support all of them in TweetDeck.
Having looked over the usage of the top 100 URL shorteners it is interesting to note that of the existing 13 supported services 3 are outside the top 100, 2 are outside the top 60 and only 5 are in the top 10. It is obvious that the current list of services is out of date and does not provide as much value as it could. To rectify this the supported services will be replaced with the current top 5 services and regularly updated. These 5 services equate to 90% of all shortened URLs in the reporting period.
Therefore as of the next full release of TweetDeck the supported URL shorteners will be (in alphabetical order):