Not according to this: http://html5test.com/results/desktop.html. BUT, IE will start to auto update their browsers here sometime soon, and in my books that's what makes a browser modern right now.
The score for IE10 is 320. It's close to Safari 5.1, the previous version of Safari, which scores 319.
Of course, it's not as high as the current leader (Maxthon 3.4.5 at 457), but IE10's got a decent score, and is definitely a big improvement compared to IE9.
You are right, that was a poor usage of the phrase "modern browser", but I'm sure you know what I meant (Chrome, Safari, and Firefox).
It is. It's just one step behind, and that's one step too far for some people.