Alex Ross, The New Yorker music critic whose "The Rest Is Noise" has long led the pack in classical-music blogging,

"The Rest Is Noise" is still up (http://www.therestisnoise.com/) and Ross will continue to post there occasionally, he writes. Going forward, though, it appears that this will be his principal online outlet:
http://www.newyorker.com/online/blogs/alexross/