Twitter is closing down the original, Adobe AIR-based version of TweetDeck, as well as the TweetDeck for iPhone and TweetDeck for Android mobile apps, reports the TweetDeck blog.

Both apps will be removed from their respective app stores in “early May”, before functionality will stop completely. TweetDeck Facebook integration will also discontinue at this time.

Twitter is blaming the decision as one of need, largely on the back on the retirement of version one of Twitter’s API, as the company prepares its move to the controversial 1.1 version of their API later this month.

Read the announcement on the TweetDeck blog (which, incidentally, is hosted on Posterous – another firm that was acquired and is now being closed down by Twitter).

In many ways, doubling down on the TweetDeck web experience and discontinuing our app support is a reflection of where our TweetDeck power-users are going. Over the past few years, we’ve seen a steady trend towards people using TweetDeck on their computers and Twitter on their mobile devices. This trend coincides with an increased investment in Twitter for iPhone and Twitter for Android –– adding photo filters and other editing capabilities, revamping user profiles and enhancing search. That said, we know this applies to most of our users –– not all of them. And for those of you who are inconvenienced by this shift, our sincere apologies.

Additionally, TweetDeck AIR, TweetDeck for Android and TweetDeck for iPhone rely on v1.0 of Twitter’s API, which we are retiring starting this month. Leading up to that retirement, Twitter’s platform team will be performing occasional tests that will affect applications that rely on API v1.0. Over the next two months users of TweetDeck AIR, TweetDeck for Android and TweetDeck for iPhone may experience some outages with those apps before they are removed from their respective app stores in early May.

To be honest, I’m not sure there are many TweetDeck “power-users” left. One time TweetDeck was absolutely the premier app for hardcore Twitter users, but those days have long passed.

Indeed, they ended right about the same time Twitter bought TweetDeck. If you’re still hanging on, I strongly recommend switching to HootSuite on your desktop, and either Tweetbot or Tweetlogix on your mobile device. Although the jury is very much out on how much time those last two guys have left – it likely won’t be too long until the only way you can access Twitter is through an official app or partner. Which, of course, is exactly how they want it.