Microsoft has been in legal limbo for the past couple years while it fought a patent lawsuit against it from Eolas Technologies. Microsoft lost the case, and as a result must change how Internet Explorer works. Eolas holds a patent that describes a method for embedding interactive content into web pages. The way Internet Explorer uses ActiveX and Java Applets infringes on this patent. So, Microsoft has chosen to make changes to IE, rather than pay licensing fees (which were prohibitive, to say the least).
I'm of mixed opinions on this. It is unfortunate that software patents could force this sort of issue. Software is nothing more than an expression of a procedure - how do you patent a procedure? But on the other hand, Microsoft is a VERY strong proponent of Intellectual Property and and using patents in an aggressive manner. So, the old saying "what's good for the goose, is good for the gander" comes to mind.
But here's the important part - any web pages that have made use of ActiveX controls must be changed to reflect the changes in IE. Every single web page. In an off the cuff admission that these changes will be disruptive, Microsoft is giving developers a one time, 60 day period to change their web pages. You can read about that on eWeek. According to the article, Microsoft is claiming that all web pages need to be re-authored. Well, that's just a little bit wrong.
You see, if I write a web page using HTML, JavaScript, and CSS, my web pages are perfectly fine. If I worte a page that uses an ActiveX component, then only THAT part of the page needs to be changed. So, saying that all web pages need to be "re-authored" is imprecise at best.
The lesson to learn here is to stick to the standards. ActiveX has never been an official standard for web development. It is a Microsoft extension to the web standards. So, in the end Microsoft controls what happens with Activex - as we are seeing now. If web developers follow standards - not the capabilities of a specific web browser - then this discussion would not be happening.