IE10 was released couple of days ago for Win7 (Win8 IE10 was released in Aug). If you would like to try it out download here:
Like IE9, IE10 has been complete ground up development from MS. Leaving all the bad publicity aside that accompanies IE, from pure objective perspective IE10 is FAST! I have started using it today and page renders are extremely fast, although in ms level, it is still perceivable.
You will definitely notice the difference if you are rending a complex site which includes HTML5 objects.
You can compare html5 render tests here, run FF & IE (performance will also depend on GPU power):
Here is another one:
Here are some real cool stuff with html5 at IE test drive site:
Anyway, if that sounded biased, its not. I have safari, ie, ff, chrome all installed and running. IE10 is a leap forward in the right direction. If nothing else, just for the debug functionality its best out there.
Here are my FF16 and IE10 numbers