The development team proposed NaCl as a potential solution to many of the format problems. We could make a lot of custom compression formats that would be better than gzip. A multitude of image formats tuned for various categories of images or videos.
NaCl project has social forces going against it. People want a homogenous platform. Platforms solve a social problem, developers become familiar with the same API, make libraries for it, make development easier, etc.. NaCl would have to play that game and it takes a long time. By the time it's done it won't be a good fit for problems of the day, just like high level VMs today.
Fast JavaScript could go a long way in that direction too https://github.com/antimatter15/weppy With types and WebGL hardware access who knows.
NaCl project has social forces going against it. People want a homogenous platform. Platforms solve a social problem, developers become familiar with the same API, make libraries for it, make development easier, etc.. NaCl would have to play that game and it takes a long time. By the time it's done it won't be a good fit for problems of the day, just like high level VMs today.