I've worked several programming jobs since switching to Dvorak, and it has never been an issue---it takes < 10 seconds to change the layout OS-wide. No need to request a special keyboard (and I leave my keycaps as QWERTY because I touch-type anyways).
I learned dvorak by printing out the layout and glancing over at the paper while typing back in high school. It took me about a month to get comfortable and I'm now basically a touch-typing bilinguist (though I'm slower at qwerty, it's more mental effort to do the conversion on the fly since my muscle memory is dvorak).