Well, Sonniss released a 10GB download initially intended just for GDC people, and like a raptor on the flock, the internet descended. Sonniss don’t mind, and mirrors are popping up everywhere, and torrents are being seeded with their blessing.
Have a look here:
The original page is here, but don’t expect to download it from there anytime soon.
http://www.sonniss.com/sound-effects/free-download-game-audio/