Tweetie 2, suddenly disappeared from AppStore. I suspect that Twitter for iPhone gonna debut real soon.

Tweetie 2 was acquired by Twitter last month and it’s developer Loren Brichter was recruited by Twitter to make Tweetie 2 as Twitter’s official app, which is planned to be renamed as Twitter for iPhone.

Couple of weeks back Tweetie 2 users received an update 2.1.2a with Slot Machine tease which shows a banner with “Tweetie will be Twitter for iPhone” when we drag to refresh the timeline.

This probably shows that. Tweetie will not get an update with “Twitter for iPhone” makeover. It’s going to be a completely new app. If you like the existing Tweetie 2, you can simply backup your app before you upgrade to Twitter for iPhone app. At the moment we can’t say whether Tweeite is removed by the developer or by Apple. If it’s removed by Apple, it can either be update to existing app or a completely new one. If it’s removed by the developer it means only one thing and that is, Twitter for iPhone will be a different new app and not be an update to the existing one.

Tweetie is the most popular and famous Twitter app for iPhone created by Loren Brichter at Atebits. Now that Twitter has acquired Tweetie, it will be named as Twitter for iPhone. Evan Williams, (CEO of Twitter) also mentioned at their blog that Loren Brichter will be working on Twitter for iPad too. Twitter for iPhone will be available for free at AppStore. (Tweetie costs $2.99).

Even Williams recently has updated Twitter blog with an open letter for all the Twitter app developers, explaining “We acquired Tweetie to grow”. This move of Twitter has shocked the whole Twitter app development community; in particular, companies like Seesmic, which are completely built on Twitter API platform.

It is also being discussed that Twitter can have better control on serving ads (through their new ad platform) if people start using their own Twitter clients and this move has more financial implications behind it than just providing a free mobile Twitter client for users.

For those of you not aware of Loren, Loren Brichter is a software developer who used to work for Apple on iPhone and now owns Atebits, the company that developed Tweetie. With this acquisition, sometime soon he’ll be joining TwitterHQ to make some really cool apps for iPhone and iPad. Loren will lead mobile development at Twitter.