Re: what pickups do artists use?
It really depends. Some pro's don't take a huge interest in things like pups etc., and let their techs deal with that stuff. You'd be suprised at the amount of people who use stock pups. Not necessarily bad, especially on higher end guitars stock pups are pretty good. (although not as good as SD's in my opinion) Personally I don't know how you can NOT be involved in your tone from the pups to the tone post all the way to your speakers, but that's me and I'm a tone freak hehe.
As for your question I think Allison from the Donna's uses primarily stock pups in her Gibsons through various Marshals. (I think she runs a Mode Four, JCM 800 and DSL 100 if I'm not mistaken)
I will say that the list of Pro's who use Duncan's is pretty big. The database referenced is probably your best source, but lots of my favorite bands of today and yesterday use Duncans. (Darkness is one example, Lamb of God, wow, just too many to mention hehe)