Here's a few things worth noting about Chrome OS.
You can turn on experimental features by opening the "about:flags" page and enabling the features you see listed. At the moment, I'm trying out the media player and the click-to-play for plugins. The click-to-play for plugins is a nice feature, since it allows me to block flash (except for when I want to play it) without needing an additional extension.
Actually, I don't think you need to enable the "click-to-play" flag. Seems that if you go to Settings > Under The Hood > Content Settings you can set plugins to require click to play without having that flag enabled. So, at this point I'm not sure what turning that flag on does.