But doesn't that destroy some of the main good points about vim? Like keeping your fingers on the same spots on the keyboard? You could re-map hjkl to whatever the dvorak equivalents and then you'd probably have an easier time navigating around.
I use dvorak with vim, and having the hjkl keys in other locations has never been a problem for me. If you know vi well you probably don't even use them that much, as there are usually faster ways to move around (e.g. "b" and "w" to move around horizontally).
Dvorak work quite well with Vim. Just use "ce", "de", etc. instead of "cw", "dw", etc.