[Update from AgentBlackBerry]: After asking around about this little tweet for a while, some clarification was given to me about it. While it was written very poorly, it actually makes sense and does not indicate that BB10 will have themes if you read it out loud.
"Details regarding Theme Studio on BB10 (the details being that it's not happening at all) will either be coming during BBJam or shortly thereafter."
There is an old teacher's adage that says, "there are no stupid questions, just those that are not asked." Twitter user Peter (@Poita316) sent the @BlackBerryDev a question they were too excited to pass up and gave the answer above. Although we yet have to see an official Theme Studio for BB7, the BlackBerry Dev team has assured us that it is still coming.
This is an exciting development as there currently is no way to customize the look of the DevAlpha, including backgrounds save for third party apps. It will be exciting to see what theme developers can come up with for the upcoming BlackBerry 10 OS as well as the PlayBook when it receives OS 10 shortly after the release of the first BB10 devices. There currently is no other way to "theme" a PlayBOok than via an obsolete rooting method.
Would you welcome themes to BB10? Let us know in the comments!