The Freakonomics podcast talked about how people respond the most to peer pressure. Marketers have known this for years. Tell someone that people just like them are doing something, and they'll typically do more of it. Steve Levitt had this to say: "From an economic perspective, shame is a wonderful punishment because unlike imprisonment, it’s free. It’s not only free but the society can impose as much shame as they want on people without any kind of cost or resources used up. But in fact, the rest of society actually likes it when other people get shamed."

This is great for consumer uses, but big corps absolutely hate not having every version of software under their control. One can argue about whether it's right for them to do it, but I have worked in too many corps where upgrading to IE 7 broke the 50 vendor-provided apps that depended on IE 6. Vendors aren't in a hurry to upgrade, and if "it just works" then the corporations won't either. Even Firefox has trouble in corporate because of their upgrade policy. Until the old-school corporate IT mentality of "well the app is certified on X browser" goes away, don't expect to see chrome, with the changing version all the time, every make much inroads into corporations.