I half-expected to be rebuked for implying some of the following in my last post, but as usual I've drawn rather less criticism than anticipated. (Whether this shows agreement, apathy, impenetrability, or something else I'm not sure.) Still, clarifications might help.
First, I have little to say on the superiority or inferiority of high versus popular culture. They're different, and while they may serve the same general purpose for humanity, the different means by which they go about it make their appeal and specific role different too.
Second, while resources and venue now tend to reflect the needs of a particular cultural mode, I don't think they necessarily form the border between the two. (Remember "Wellington's Victory"? -- The reverse, high-cultural expression in pop clothing, is also possible if beyond the scope of this blog.) For example, despite concert-hall presentation, DG record deal, and skillful writing for classical instruments and voices, Osvaldo Golijov is quite clearly a popular musician. That is to say: opera being 99% a high-cultural genre, if you're looking for a savior (or future) of "opera", Golijov isn't it. I'd go so far as to say that unless he's been looking to change his aesthetic tune for a while, the Met shouldn't be spending its limited new-music resources on him.
Third, obviously this and the preceding post are not a complete theory of cultural modes. More tidbits do turn up if you search the blog for "popular"...
UPDATE (8/2/07): A commenter notes this possibly-apropos review.