Linux kernel 2.6.38 has arrived in Debian backports. I installed it using the guide at backports.debian.org. Linux kernel 2.6.38 contains a much-hyped wonder patch.
I rebooted and observed... no noticeable difference in performance. But then I wasn't running a HD movie, compiling a complex program and running a 3D game stress test- if you do, you might.
The patch is also reported to improve web page load times with a busy CPU, by non other than... Linus Torvalds.
Now if only I weren't such a slacker my CPU might be busy enough to test this, but no.... CPU usage at about 5%.