I think that they are definitely musicians when they compose the stuff they are playing on their turntables. For example when they play with a band.
Also when they are playing un-oruginal samples in an interesting context. For example, Asian Dub Foundation, I am a big fan of them, they play electronic music and the DJ is adding some samples from traditional Indian music and the effect is awesome.
I generally respect DJ-s who play with a band much more than those who just mix music at a techno/whatever party, cuz it takes in my opinion greater skills to play with other musicians, to be able to communicate with them.
I'll be definitely looking for band with a Dj because I believe that the future is in the extensive use of technologies. And it looks kind of dumb to go on stage with a PC and to play the samples from there. It is much more cool to have some person(s) who operates with the turntables and drummachines.