I've been reading about the new 3.12 kernel and I am excited about the increased performance reported by Phoronix.
How long will it be before Ubuntu releases include the 3.12 kernel?
Ubuntu is about stability over newest versions.That includes the kernel.
13.10 is using 3.11. I doubt it will be included into 13.10. I would expect it to have been included during release if we would get it.
So I believe you will probably see kernel 3.12 in Ubuntu 14.04.
But no-one it stopping you from including it. Some older topics, but the method is still valid (just need to update the file names):
Topics related to installing 3.12:
Just a warning: this is not for the fainthearted. And messing up might mean a re-install. And as always: make a back-up. Or even two.