About hyphens, you have to use them, whether you like them or not, otherwise your custom element is invalid. I don't like upper case characters in tags, but that's just personal aesthetics, there's no rational reason behind it.
About web components, I really love the ideas and can't wait for wider browser implementation. I'm especially excited for HTML Imports, though Mozilla has been stalling that one. It's really bad for usability to have to tell people to import a bunch of files into their page to use your library, whereas with HTML imports they just import 1 file, nice and clean.