The Ubuntu Touch Developer Preview has been released. This includes the source code and images for both the phone and tablet interfaces and are aimed at developers so it's not something you should install for actual every day usage. For now you'll find that some features are missing, like playing music, no mobile data connection, PIN/PUK support, etc., there are bugs and so on.

Just like more than a month ago, when Ubuntu Phone OS was announced, a countdown is displayed on the Ubuntu.com homepage, and this time it says: "Tick, tock, tablet time!".

So what could this be? An Ubuntu tablet is about to be released? Or more likely, an optimized Ubuntu Phone OS for tablets?

Update: this might be a coincidence (?), but if it's not, it's big (via +Nate Carpenter)! Below is a screenshot of ubuntu.com and htc.com, side by side:

The mysterious "so close you can almost touch it" countdown from the ubuntu.com website has just expired, revealing a new operating system for mobile phones: Ubuntu Phone OS.

Check out the trailer and Mark Shuttleworth's presentation of Ubuntu Phone OS videos below:

Because there aren't too many touch-enabled devices so only a few people can enjoy the touch functionality in Unity (Ubuntu 10.10 Netbook Edition), the guys at Canonical blog posted a video showing off the amazing multi-touch capabilities of Unity: