Fox announced it this afternoon! I'll put the link up to Variety, but if you can't read it, basically it says the numbers don't warrant the rise in production costs that a 9th season would cost. House has averaged close to 8 million an episode thus far. It's still one of their higher rated shows, but those production costs....
http://www.variety.com
HERE'S a more indepth link from GMMR: http://www.givememyremote.com