Ask HN: implementation of W3C clipboard APIs?

It'd be really nice to write web apps that interacted properly with the OS clipboard.

There's (non-standard) support on IE, and one can write to the clipboard using Flash-based hacks like Zero Clipboard (http://code.google.com/p/zeroclipboard/), but the state of the art makes it impossible to write a web app that functions as the user expects.

It turns out that there is a W3C working draft "Clipboard API and events" at http://www.w3.org/TR/clipboard-apis/.

I'm surprised to find that this hasn't been implemented yet.

Could those with experience on the major FOSS browsers share the reasons for that? There are a lot of devs wanting it, so presumably there's a good reason that it hasn't been done.

Or is it simply a matter of effort & prioritisation? Would one of the FOSS browser projects (Chromium, FF) accept a patch with clipboard API support if it were proffered?