Microsoft Office Mix looks interesting, but after 5 minutes of scratching the surface, seems to have holes in it.
Doesn't currently work on Macs? (it's not even fully cross-browser compatible). It's not clear if it works with Office 2016 on OS X or not. That may have just killed it.
It's not clear what MS means by "polls". They seem to mean multiple-user input quizzes for online presentations (as in "Facebook poll"), rather than live event polls a la TurningPoint - but I may have got that wrong?