I've been using Colemak for about 3 years, haven't touch typed QWERTY since. I have a Kinesis keyboard at work and another one at home on my main computer, the Mac minis for TV and beamer have Apple bluetooth keyboards, but are mostly controlled with just a mouse (with lots of buttons, and each button is used). No one else uses these keyboards normally (no GF/wife), and if someone does it's easy to change the layout (though hardly anyone wants to use the Kinesis themselves, so they let me type).
Whenever I have to type somewhere else I either use hunting and pecking in QWERTY for little text, or if I have to type more than 2 minutes I switch to Colemak (install if needed). As long as it's Colemak I can touch type on other keyboards well enough to get by.
Funny enough since typing on an smart phone is hunting and pecking by design I don't miss Colemak much on there - whenever I actually look at the keyboard I want to type QWERTY anyway.
The switch to Colemak was hard, even though not all keys change compared to QWERTY, you can read all about it in the Colemak experiences forums. For me the first week was hardest, because every. single. key stroke. was a conscious decision, after 3 weeks I was half as fast as before and from there on it was easy going.
If you persist and don't do it when all hell is loose at work it should be fine. You'll be incredibly slow when typing IM or Email or anything, so if long texts are due it's a bad time. I did it when I wasn't programming as usual, but building a GUI prototype, which involved more clicking than typing.
I figured the switch was worth it given I'll likely write software for the next 30 odd years, but in our company with over a hundred programmers there's surprisingly few who'd consider such a switch.
Some guys retain their QWERTY touch typing skills. I haven't even tried to be honest. I think during the transition it would have been harmful. But now that Colemak is ingrained I think I could handle attempting to know two layouts well enough to switch at will, but there's no need, so I haven't tried.