rpi-update is currently giving a 3.10.18+ kernel
Updating to this just rendered two of my 8GB SDcards unuseable.
The sequence of events appears to be as follows:
Raspbian appears to boot normally up until you see "Mounting Local filesystems..."
OK light remains stuck ON and you get:
mmc0: timeout waiting for hardware interrupt - cmd12.
mmcblk0: error -110 sending stop command, original cmd response 0x900, card status 0xf00
as this consistently happens across several cards and several different RPi and both cards and Pi work fine when reverted to the 3.6.x kernel it would appear there's some software incompatibility with certain cards. Yes, the same Pi with this new kernel on a different SDcard works fine.
So as a cautionary tale, don't do what I did and run this update remotely or you might end up in the situation I did of having to get a ladder and physically retrieve the Pi to find out what went wrong.