I was a qwerty typist for about 7 years, when I noted that I could touch type fluently. I started typing colemak around the time that it won the capsfree contest, but couldn't get it to stick. This year, I tried again, and I was again unsuccessful. But, in school, the marking period ended, and I had a long trip, so I took the time after the marking period ended to go colemak cold turkey, and I used the trip as an opportunity to hopefully weaken my qwerty muscle memory so I could switch.

When I came back, I worked more on the ktouch typing lessons, and took a typing test, which was about 28wpm. When I finished the lessons, I was about 33wpm, and a couple days later (school started, still using colemak, I'm at 38wpm.  My previous qwerty speed was around 58. I also took this opportunity to maintain perfect touchtyping form, so hopefully my index fingers will hurt less.

Im typing on a mac, and using caps lock for control, since i want my backspace key to repeat.
CORRECTION: to get caps lock to be backspace (with key repeating, use This System Preference

Wed Apr  2:
Took a couple of the typing tests, most were around 50 wpm, using colemak.