I actually don't believe for a moment that the resurgence in IE development we've witnessed has anything to do with EU's efforts.
I think it's unfair to the hard work of Mozilla and later Google Chrome development teams to claim that their achievement is actually a result of some cheap political posturing by EU. What actually made Microsoft develop IE again is the fact that Mozilla has succeeded in delivering a more stable and feature-rich (and easy to use!) web browser for several years. In fact I am afraid that this trend might be reversed now that Mozilla started chasing Chrome in version treadmill. (I have only anecdotal evidence but it seems that plugin compatibility and stability suffered as a result)