But do you agree, is the end of commercial, proprietary platforms within the corporate marketplace really nigh?
It's quite likely that large corporations might start switching - after all, many are fed up with the long wait of Vista, the bugs it brings, and so forth. They need new features, and need them soon.
However, I think large corporations switching to Linux may also be a trend that will eventually come to an end. Recently, we saw the Georgia Public Library switch to open source management systems, the French Parliament, and earlier Munich switched to Linux. This may partly be due to being fed up with their Microsoft systems, but it's also something along the lines of "hey, if the French parliament's doing it, it must be alright."
Another thing is that I suspect that the costs of training employees to use the new systems will also come back and bite the corporations in the butt. At the moment, Microsoft has a big advantage: not only do they dominate the consumer operating system market, they also dominate the corporate operating system market. Employees likely already have Windows XP computers at home; so training new employees is very easy at the moment. If larger corporations switched to Linux, the training costs would increase dramatically as they force their employees to switch.
So although it's cool to see corporations take advantage of open source, we really can't tell how much money and hassle it saves them until they've used Linux systems for a while. But if I were Microsoft, I'd keep an eye out for Linux. Especially now.