I think there are already a few voice/video conference extensions ...

you have have keystroke updates instead of waiting for the entire line to be inputed

c'mon ! It's April first in New Zealand .
Look at this :
IE 8.1 Supports Firefox Plugins, Rendering Engine
Posted by kdawson on Wednesday April 01, @08:28AM

If I remember right, IE was the first filemanager/browser in one. I believe it was IE3.0 ...