Some people want these effects. Without them, the choice is to write it all by hand using canvas, or use animated gifs or Flash or something. Sure, there are v

Some people want these effects. Without them, the choice is to write it all by hand using canvas, or use animated gifs or Flash or something. Sure, there are varying levels of support of the most bleeding edge features, but browsers are catching up with each other all the time. For real world sites, you use what's widely available, which corresponds to the gee-whiz demos from 5 years ago (give or take, and depending on how many truly obsolete users you need to support). So yeah, this isn't really all that useful outside of a gee-whiz demo now, but in a few years all of the major browsers will support it and people can use it. This kind of effect is most likely to be used in a game that has a large asset library to load, but the underlying functionality can be useful in a variety of designs.