I thought I should chime in here and revive this thread because the topic is of great professional interest to me.
Eleven months ago, I fell in love with an Englishman, at the same time that I was withering away in a lousy job in the US (in breast cancer advocacy) that I really do think took a toll on my health. When I met A, I started thinking about the NHS and all the truly cool things they're doing to ensure health care for all, deliver care efficiently, and improve the quality of care. I wanted to learn more. So I soon decided - at his suggestion! - to move here and work and learn more. And of course to be with him...
To answer the original question, at least professionally speaking, the NHS was indeed a factor in my moving here. Although I personally had pretty much always gotten most of what I needed from the US health care system, there was one occasion when I was freelancing and on cheap, temporary insurance in between full-time jobs and, upon submitting a claim for an orthopedic exam for back pain, I got a creepy letter from the insurance company requesting all my medical records for the past 5 years. I decided I would rather just pay the bill myself than send in my records and become a victim of some pre-existing condition exclusion (yes, in fact, I did have pre-existing back pain! but that might have been enough to cut my coverage off entirely). It is a great relief to be freelancing in the UK and no longer having to worry about that sort of craziness.
Finally, I am putting together a blog for a health policy journal on this US consumer's experience in the NHS, examining some of the preconceived notions that Americans - not necessarily those on this forum! - have about UK health care. So everyone's observations here are very helpful, and I may even contact some of you to discuss a little further (your experiences would, of course, be anonymous). Thanks!