You should still be able to run all of these in Vista with some tricks. I found this post on a Polish forum where someone managed to run IE10 Preview in Vista by just copying the files manually.
Wow, no kidding!? You can simply copy the IE10 files over to Vista, and it will work? That sounds so
This is amazing. But, doesn't IE10 have to get "installed" in some way? I can see the method working if you launch IE10 directly (from a shortcut that you manually created, or in Windows Explorer), but what happens if you click on a link in a Windows Help file, or on a link in an e-mail? In those cases I have to think that Vista would use the "official" installed version of IE, right?