I'm working on it this very moment. (:
Before you get your hopes up too high, I should point out that the iPad 3's retina display has 4x as many pixels as the iPad 2, while memory bandwidth is only around 1.5-2x -- so it's not clear yet whether Aquaria will run at full speed at full resolution (Aquaria is limited mostly by graphics memory bandwidth). That said, I do think it should be possible to push the resolution up at least somewhat.