Google has many competitors, Microsoft being a major one but certainly not the only one. I doubt there is any foul play going on. Keep in mind that Google is a company, and a big one at that. They have a lot of monopolistic advantages. Whether or not they abused them is in the eye of the beholder, but they certainly have a hold on many different parts of the tech industry.

The compatibility issues are due to them having non-standards compliant code in the first place. Who is Microsoft to tell the world to use something different then what the W3C defines, and further, who are web developers to listen to them? (Other then the largest software company in the world, of course). I'm thinking the list is designed to be a shock list, to make (uninformed) people think that standards compliance is a bad thing, and the evil W3C needs to be stopped (similar to Microsoft-backed SCO claiming GPL was unconstitutional? http://www.linux.com/feature/32357). Most likely, it's a bluff. I can't imagine Microsoft releasing a browser that doesn't fully work with their own website, nevertheless Google and the others. That would piss off more people then just releasing a non-standard browser would. In the end, they will probably keep their non-standard technology like Active X and the like. It's going to be up to the website developers to tell Microsoft to RTFM (the one published by the W3C) - by not using their archaic functions and making websites that follow standards, and not just Microsoft imposed rules.