It is funny that you pose that question. I was just looking at the origins of the QWERTY keyboard and followed links to Dvorak's keyboard. I enlarged the keyboard in Wiki and began air typing on it. I think that it might greatly increase the speed of typing on the Storm, even though you have to coordinate you alternate finger taps. I know when I am typing on my computer keyboard I don't have to look down, but on any smartphone I have ever used, including my HTC XV6800 WM (yeah I know) and the Samsung i730, both of which does have physical keyboards, I always have to look down. It would be great to have a more efficient keyboard or at least an option.
Just a short note here to let you folks know that I have created a software for touch typing Dvorak users on the AppWorld. I can't post the link herer as my post is less than 10.
But you can search for it in the AppWorld or in Google for Dvorakize