In an interview with About.com, Shia La Beouf mentioned (in passing) that he would like to have an involvement in a transformers sequel. Nothing concrete and no confirmation that he has signed on but it’s a postive angle at least.

Shia LaBeouf: “I was thinking about quitting this industry. And Michael Bay will tell you that. He’s so hard on his actors, [...]

Why didn’t you walk off the set?

Shia LaBeouf: “Because it was too important to my career.”

You’ll never do that again.

Shia LaBeouf: “I mean, until 2 and 3.”