This is incredible and is going to be very useful for people developing applications for use in Eastern Asia. Nailing typefaces for Chinese, Japanese, and Korean is a huge challenge. Noto and the accompanying Source Han Sans is going to be a huge boon for people in Eastern Asia and hopefully it will have widespread adoption.

Sadly, it's probably still not possible to use as a Webfont. A single font weight is over 8mb, but there is a distinct possibility this could go into mobile devices and operating systems which would be awesome.