Chromium OS, the open source project for Chrome OS, recently switched from Linux kernel version 2.6.32 to the latest version, 2.6.38. It's likely we'll see 2.6.38 hit Chrome OS in a few weeks with the first 0.13 dev-channel builds. To give you a rough idea of the difference in age between the two kernels, Linux 2.6.32 was the kernel for Ubuntu 10.04 released April of 2010 while 2.6.38 is the kernel version included with Ubuntu 11.04 released just last week. That's not a perfect picture of the difference between the two because it's likely Chrome OS developers backported some of the best patches from 2.6.33 - 38 to their 2.6.32 tree but backporting patches never offers all the benefits of moving up to the latest kernel.
Keep your eyes peeled for 0.13 and the new 2.6.38 kernel.