I agree with Steve's point, but he's mostly talking about typing fast to participate in online communities, write more e-mails, etc. That sort of stuff doesn't require a "programmer's" Dvorak keyboard - so my point still stands. The act of programming doesn't require extremely fast input - especially as a lot of people use macros and shortcuts now anyway.

Using Dvorak to be a better participant in online forums, etc, is awesome, but you can use a regular Dvorak keyboard for that.