This is huge. Not only does it let you get entropy without having to open a device file (which has problems with chroots and file descriptor exhaustion), it also provides the much-needed middle ground between /dev/random and /dev/urandom. Assuming this patch is applied (it's from Theodore Ts'o, so chances seem good), Linux will finally have a decent way to get randomness, which would make me very happy.
Hopefully proper fork detection will be next up.