No, not just things like the Three Tenors topping the charts. With things like symphonic and operatic metal coming into the main stream, which pop or metal singers have an opera background, and can you think of any opera singers who do pop/rock or metal? Tarja Turonen is the main one I can think of, but are there any others?
No I don't, but you piqued my interest. Bohemian Rhapsody is the only crossover I know about, but Freddie Mercury was a rock singer who crossed over for that one song. Having an opera singer crossover for rock versions of operatic songs would be interesting.