[notahacker]

"Web 2.0" was a lot less about aesthetics than "flat design" (the emergence of custom font solutions that didn't require Flash or graphics was the real revolution; the "flat"-ness itself is just a fad, and for that matter HN has been pretty flat looking for a while now!)

The browser wars deserved a mention, probably in the Javascript section too, and the death of the "web safe" palette.

Embedded video everywhere is probably the biggest boon to designers in recent years, even if it's been theoretically achievable since Flash came onto the scene. Or earlier if you count animated gifs