As I had hoped, and according to this article, the laptop will have Squeak installed:

I didn't get to see the software being designed to operate the machine, but learned a bit more about the team working on it. A small team of Red Hat engineers are customizing a Red Hat distro to the processor and hardware specifications of the machine. They're doing some work on the GUI as well, as are Alan Kay and Seymour Papert - the total development team is about 18 people, including Kay's students at the media lab. The machine will come with tools to encourage students to experiment with programming, including Squeak (a graphical environment for the Smalltalk programming language) and Logo. The plan is to make the software available online in a few months so that testers can bang on it and suggest features.