According to a Mojang representative, the Xperia Play version will have customized controls for the phone's PlayStation-style controller layout. The rep also hinted at the nature of the release, saying it'll fall in line with the studio's previous "release early and update frequently" model.
Given the previously announced "2011" release window for the mobile version of Minecraft, and the studio's upcoming "Minecraft-themed media event" at E3, we expect to hear much more in the next few weeks.
[Update: Developer Markus Persson just tweeted the above image, writing, "This is the project Aron and Jens are working on."]
[Update 2: Via Engadget we've even got a video of the game running on an Xperia Play which you'll find ... you guessed it! After the break.]