You are neglecting people like Penderecki and Rautavaara who are living and write symphonies, sonatas etc....
I don't really know Penderecki outside of "Threnody", which is a wonderful piece, imo, fairly reminiscent of some of Ligeti's work like the well-known "Atmospheres". In general I tend to be a bit of an early 20th c. classical fan, and most of those guys are unfortunately no longer with us. I do however greatly enjoy the work of some of the "spectralist" composers I've heard, such as http://www.youtube.com/watch?v=HRuxHVWfQtA, who is still living.
I'm actually a "classical" composer myself, looking on to put on a recital of my original work this semester so that I might graduate. Though to be fair, I do heavily use rock instrumentation, but my music is fully scored out and regularly applies principles of harmony, counterpoint, and development.