While Twitter has been continually updating its desktop apps and desktop browser experience, its mobile site has been sorely lacking – both with regards to design and functionality. Today, however, Twitter announced that it is launching a new HTML5-based version of its mobile site for smartphones and tablets. This new design will roll out slowly. Today, only a select number of users on iPhones, iPod Touches and Android smartphones will see the new site, but Twitter plans to roll this new version out to all users over the next few weeks.

This new version will replicate some of the functionality of the new desktop version of Twitter. Tweets with images, for example, will display previews of these photos and you will be able to easily switch back and forth between @mentions, messages, your lists and trending topics with the help of a navigation bar at the top of the screen.

Given that Twitter already offers native apps for these platforms, upgrading its mobile site was likely not a priority for the company. At the same time, though, it’s good to see the company finally upgrade the mobile web experience.