I don't have to ask. I can turn on a TV during normal working hours and see how many of my local lawyer's do specialize in med mal. In fact I have one in my Reserve unit. He has often said that one of the more lucrative things he can do is sue and subsequently settle with hospitals over old folks or kids.
You might want to ask him about his practice in detail - you'll be surprised.
It's really an interesting phenomenon - when I was in law school, everyone who commented on it warned against med mal as a business model. Of course I also learned how much tougher and more expensive it is to sue a doctor.
When I got out and started working, all the PI/ambulance chasers I knew took med mal cases only on the rarest of occassions - too expensive and too much of a crapshoot otherwise. Yeah, everyone knows John Edwards made a fortune on it, but everyone knows Michael Jordan made a fortune playing ball too. Edwards is the legal equivalent.
The only place I can find people who know how profitable med mal lawsuits are is outside the legal profession.