"I said I was taking off a year from Transformers," Bay wrote on his official forum. "Paramount made a mistake in dating Transformers 3. They asked me on the phone. I said yes to July 4—but for 2012—whoops! Not 2011!!! That would mean I would have to start prep in September. No way. My brain needs a break from fighting robots."
The post confirms at least that Bay is considering directing the third installment, about which there has been no other information except the release date.