Yeah, I seen similar horror stories. I have also seen migrations to Linux (small insurance firm) that was far less painful.
The actual migration went pretty well, after three years of planning, regression testing, and fixing problems. About 99.9% of the stuff that was supposed to work did.
I turned in my XP laptop, received my Win7 laptop, and was running in a few hours. You got your favorites in the browser, all your mail was there, and the standard applications deployed themselves perfectly.