They also removed support for the MMS protocol. This is still used by some companies to ensure webcasts work properly, normally audio only.
If you install WMP11 they dont work unless they can rollover to HTTP.
Only really affects you if your in an office behind a firewall. We have several Users at work who sit through an hour or so of an audio webcast
The links start with MMS:// instead of HTTP://
RTSP is better and more reliable, they start RTSP://
I could go on but your probably asleep already..