With reference to the above HTML WG bugzilla thread, I would like to request a mechanism by which authors can easily detect whether a particular DRM scheme (in the context of some media which may or may not otherwise be playable) is supported by the UA. At present I believe there is no way to do this in advance (e.g., by way of .canPlayType()), the UA must load at least some of a source media resource in order to determine playability, and so a parallel to canPlayType() (or an extension) to it would be advantageous. Given that most (all?) DRM schemes seem to be implemented in the context of particular container formats, it would make sense to me for the scheme to be queried together with the container format and possibly codecs, possibly as a single string (e.g., a drm= parameter on the video/ or audio/ MIME type), but I don't have hugely strong opinions on it. I'd just like a mechanism which works. (I realise this is a relatively contentious issue; suffice to say, my opinions of DRM are probably pretty much the same as yours).
@Eric, @Jer, @Dana, @Jean - anything to do here?