http://www.pcpro.co.uk/blogs/2008/11/10/windows-7-faster-or-just-smarter/  Quote from their article:

“The actual performance gap between Vista and Windows 7 is ... nada. Absolutely nothing. Our Office benchmarks and video encoding tests complete in precisely the same time regardless of which OS is installed. [...] It's tempting to see this as a bit of a con. They've sped up the front end so it feels like you're getting more done, but in terms of real productivity it's no better than Vista.”

The productivity would actually increase if the front end speed increased since it would allow the user to interact faster etc. The other tests such as encoding etc are really CPU and application dependent and not very much OS dependent. Video encoding is a terrible metric for "productivity" since it's something the computer can do on it's on while you go get coffee. It's pretty much CPU and memory bound. The underlying OS shouldn't be doing anything but getting out of the way.  I would however like to see the same tests run on XP and see how much of an improvement it offers.

The last good thing I’ve seen on Windows7 is that dwm.exe uses a whole lot less memory than on Vista. I am still waiting on a build with the new taskbar to see what that does to the memory footprint that may bring us back to Vista response times and memory usage.

From the WSJ http://online.wsj.com/article/SB122602394113507555.html Dr. Gero Hutter, a physician in Germany, replaced the bone marrow of an HIV patient with the bone marrow of a donor who has natural immunity to HIV. The new bone marrow in the patient then produced immune-system cells that are immune to HIV. Being unable to hijack any immune cell, the HIV has simply disappeared. The patient has been free of HIV for about 2 years.

Some more info on HIV immunity over at wired http://www.wired.com/medtech/health/news/2005/01/66198