IE scripting engines
Since then, the Active Scripting languages became general purpose-scripting languages for automating general functions in Windows, much to the delight of system administrators and virus authors. They were also used in creating Active Server Pages. But people forgot along the line that they were modular and extensible, except in the "you can disable them for security's sake" sense.
So. I propose that somebody (You, maybe? Not me, I'm lazy.) create a new implementation of ECMAScript as an Active Scripting language, perhaps by leveraging some of the code from Mozilla. Except, in this IE scripting language, you'd be able to disable individual events, or modify how they fire.
The benefit? Lots of things. You could, of course, disable the firing of the window.open command from within the onload or onunload events of the page, thereby killing popups in the same elegant, effective, and appropriate manner that Mozilla does. But there's probably a lot more you could do by giving the huge user base of IE/Win users this flexibility. And you'd have the only scripting language that would have a user base that included end users in addition to developers. Bonus.
Get to it, kids!