According to Ralf Weber, tournament director of the Gerry Weber Open in Halle, Roger said to him in London that he wants to play the tournament in 2012 in order to make up for not playing there this year.
It would not surprise me if he skipped Toronto. The schedule is packed from early May to early September. I wouldn't even be shocked if he skipped Cincinnati too, especially if he plays a lot of matches during that stretch. Lots of other guys will be taking a breather before the US Open too. Skipping Miami would also open up a longer training/recuperation break before the clay season.