"As Microsoft allowed people to take an early version of Windows 7 out for a test ride, the "-Killer" suffix re-emerged. It's not an "OS X-Killer." It's a "Linux-Killer." I'm sure this is due in large part to the robust netbook market and Apple's absence there. It's interesting that suddenly Linux is seen as competition. It's also intriguing that this is portrayed as the nail in the coffin, and not an opportunity."

article about the strategy one might suspect microsoft to be following
from the site:
"This is a blatant and arrogant slap to the face for netbook users. With it's three application limit, Windows 7 Starter Edition is more or less Microsoft's way of saying that netbooks are substandard PC's, and their users are substandard people only interested in a cheap product, and not the "more powerful" (read more expensive) hardware you should be using."

These guys have tested ubuntu vs windows vista and ubuntu vs windows 7 for performance, from the site:

In depth: A lot of people have been chattering about the improvements Windows 7 brings for Windows users, but how does it compare to Ubuntu in real-world tests? We put Ubuntu 8.10, Windows Vista and Windows 7 through their paces in both 32-bit and 64-bit tests to see just how well Ubuntu faces the new contender. And, just for luck, we threw in a few tests using Jaunty Jackalope with ext4.