Linus sought to drag out the Linux 3.13 kernel development cycle so the final release wouldn't collide with LCA 2014 nor the opening of the merge window during his travelling time. Linux 3.13 should come in about the middle of the month, or another week.
No official release announcement for 3.13-rc8 has yet to come from Torvalds on the mailing list or Google+ but the Git tag can be found. In continually tracking the Linux kernel Git activity, I can tell you though that 3.13-rc8 isn't too exciting. There were less than 100 Git commits since -rc7 and it appears to be mostly mundane bug-fixes, etc.
In terms of the major features being introduced in the Linux 3.13 kernel, see last week's article The Linux 3.13 Kernel Has Many Improvements.