Linus Torvalds wrote in the late Saturday 3.10-rc5 announcement, "I wish I could say that things are calming down, but I'd be lying. rc5 is noticeably bigger than rc4, both in number of commits and in files changed (although rc4 actually had more lines changed, so there's that). Guys, guys, guys. I'm going to have to start cursing again unless you stop sending me non-critical stuff. So the next pull request I get that has 'cleanups' or just pointless churn, I'm going to call you guys out on, and try to come up with new ways to insult you, your mother, and your deceased pet hamster."
The Linux 3.10-rc5 changes are scattered throughout the various subsystems to address various outstanding problems, but Linus hopes the 3.10-rc6 and later RCs will only be about fixing serious regressions.
Linus ended this week's announcement with, "Go out and test. And again - please don't make me curse you and your pets."
Some of the most pressing changes for the Linux 3.10 kernel are covered in this Phoronix article.