I'm a long way from being an expert in the area so I won't comment on this exact situation, but an overall thought: the difference between MS and Google is that MS wanted a monopoly and were generally quite sloppy, whereas it's in Google's interest to have a faster internet for everyone, not just their users, plus they have the ability to push for adoption of features developed for their browser/servers, which could lead to other browsers, and servers (would it be Apache/etc. that would have to implement it?) adding SPDY support.
How is that different? MS wants marketshare, Google wants marketshare, faster internet for everyone is just a means to an end: more people using Google services. I'm sorry for not buying into the Google-hype, but keep in mind they're a business like everyone else and they are in it to make money. If you ever need proof that Google is doing this for money like everyone else, just take a look at the history of their advertising services.
I'm not saying that Google isn't doing this for business reasons - it just happens that in Google's case, they benefit more from all browsers being better than trying to make Chrome kill off other browsers.
This is similar to Microsoft happily pushing and supporting new bus/interface/port standards to allow many various hardware companies to bring newer, better, faster hardware to the consumer.
It wasn't because they were nice or had the consumer's best interest at heart. They just wanted PCs to be faster, because they had a monopoly that sat atop PCs. So they benefit when PCs get faster, get replaced and stay ahead of would-be competitors.
