Back in the day, Microsoft would use a strategy called "embrace, extend, extinguish." http://en.wikipedia.org/wiki/Embrace,_extend_and_extinguish

Recently, Microsoft has been pushing Javascript very hard (embrace) and now it looks like they've started the "extend" phase.

Luckily, no one really worries about them being able to pull off the "extinguish" part anymore... they just don't have enough market power these days.

EDIT: Yes, I conceede the fact that TypeScript is OS probably addresses most of these objections.