As a full time dvorak typist I can tell you that it has definitely helped with my RSI (as has using vi). Dvorak is comfortable. It's hard to explain, but it feels like one's fingers are "rolling" over the home row when typing.
Second, who said having the all on the home row is better? Studies --nit Dvorak's own-- have shown marginal or no improvement compared to qwerty, ven for typists.
About the having keys on the home row, I certainly claim it is better, and you should try it for yourself. I will concede that it may not give a speed increase for a seasoned typist, I suspect that at a certain point when everything is in muscle memory it doesn't matter anymore. However, having to move your fingers less is simply less straining, so it will be more comfortable. This was not measured in those studies, so that's why I think they are not relevant.
It's a really cool keyboard. I wish Apple brings it's thumb+index finger twist [2] to do Ctrl-W to their laptop's touchpad. You can see the roots of their pinch to zoom gestures all in the keyboard, and it had much, much more. Apple acquired the company and it's IP in 2005.
[1] http://en.wikipedia.org/wiki/FingerWorks
[2] Actually, it might have been 4 fingers (minus pinky) twist. It's been a long while. I'm sure I'll remember how to do it once I have the keyboard in front of me. Just like vi keys.