Yes, we're aware CCFL displays eventually wear down and lose their brightness, but either there really is a huge difference in CCFL and LED, or the 8-month old MBP we tested against in the photos had really worn down. Our suspicion is that it's a bit of both.
Standing in front of the white-LED backlight on the new MBP, it's immediately apparent how crisp the whites are -- it's very noticeable after staring into CCFL LCDs all day long. But even though the whites were whiter, the screen didn't necessarily seem a lot brighter, which is probably where some amount of CCFL dimming on our test MBP came into play in creating the dramatic difference we saw. Viewing angles were very similar on both machines, but as you'll notice, at half brightness it's the LED backlit MBP that's dimmer, and the CCFL display that's actually brighter. Interesting stuff.
Note: People, seriously, the commentary about the desktop contents on the CCFL test laptop is irrelevant. We borrowed the 2nd gen CCFL MacBook Pro it to do the test, ok? (Ours is a 1st gen MBP, which was a little older and would have surely skewed the results of the screen test.) Just so you can rest easy that we're not evil bad men pirating MPAA movies you can compare the serial numbers from our MBP with the MBPs tested in this post: