Some browsers can do all of those things - but you've still only scratched the surface of what Flash can do TODAY with 98% penetration. As for webcam support, some people feel that HTML 5 as a spec will be fully out there and usable by 2022. I wonder when enough browser makers will start on their PROPRIETARY webcam interfaces?
Do you think Flash will stand still in that time? Suddenly jump from 98% to 0%?