Why bring a game into a browser? Rather than get frustrated with the lack of compatibility and bugs which are concomitant with A PORT TO A *WEB* *BROWSER*, I'd rather double click on the little picture with the TF2 logo, wait 15 seconds, then start playing with no issues, no lag, no FPS issues, and definitely no graphics issues.
I don't want a web browser that is a "jack of all trades, master of none". I don't care if I have to run more than 1 program. That's what RAM is for. I'll open a window for gaming, and I'll use my web browser for browsing. Period. Just concentrate on giving us the best web browsing experience, and your market share will rise.
A web browser is just that: a web browser. Don't do this. TF2 deserves better.