With the acceptance and use of HTML5 and WebGL, browser-based games will no longer will be limited to 2D graphics and limited interactivity. By using these new technologies, browser-based gaming will be more likely to look like what you are used to seeing on gaming consoles.
WebGL will allow developers to create games which feature accelerated 3D graphics, and HTML5 enables the use of real time audio manipulation. WebSockets allow the use of bi-directional networking, which in turn enables games with low latency, and quicker response times.
We’re already seeing new browser-based games on the market, including Quake, DOOM and others, but there are still obstacles to overcome, including the lack of game controllers, dual player support and no motion-based input. Give developers a bit more time, however, and those problems will be overcome via additional technology.