Linus Torvalds has announced on Friday, November 22, 2013, that the first Release Candidate of the upcoming Linux kernel 3.13 is now available for download and testing.
In numbers, Linux kernel 3.13 RC1 is comprised of mostly updated or new drivers (55%), architecture code (18%), network updates (9%), and the rest of of 28% represents filesystem updates, tools, headers, and documentation.
"So you had an extra week to prepare your pull requests, and if you were planning on sending it in the last two days thinking I'd close the merge window on Sunday as usual, I can only laugh derisively in your general direction, and call you bad names."
"Because I'm not interested in your excuses. I did warn people about this in the 3.12 release notes. As it was, there were a few people who cut it fairly close today. You know who you are." said Linus Torvalds
Featurewise, the big ones are likely the nftables and the multi-queue block layer stuff, but depending on your interests you might find all the incremental updates to various areas interesting. There are some odd ones in there (LE mode Powerpc support..)
You can download the latest rc1 from kernel.org website.
Note: Remember that this is a development version and it should NOT be installed on production machines. It is intended for testing purposes only.