Windows 7 is great, but charging extra is going to do what the author warns - put it out of reach by driving up costs.
Why are netbooks successful? Because they're CHEAP. Sell LOTS of a cheap product with less margin rather than sell just a few of an expensive product with more margin. By appealing to the masses, you move more units, and with the economic state the way it is today, that's the strategy it will take to win. You've got to sell high quantity.
Asus took the world by surprise with the EEE PC, and now everyone is playing "me too." Competition is fierce, and margins are slim, but they are making some money on netbooks. By selling lots of them, they make more. There will be OEMs that might refuse to buy WIndows 7 licenses, and even switch to a non-windows alternative if MS raises the Windows 7 price too high. There's NO WAY an OS with so many feature and functionality limits should EVER cost more than a perfectly functional copy of XP. I've NEVER seen a netbook with XP on it that I can't at least change the stupid wallpaper on.
This is getting ridiculous. I love Windows 7, but when I buy a netbook it's going to be based on PRICE, not whether it has Windows 7. If it costs me more to have seven on my netbook, screw it. I don't need it to surf the web and do "small notebook PC" activities. XP, Linus, hackintosh, whatever ... they are all fine for a netbook.