So can html5 continually ping a variable (say a time point) while a video is playing, including other variables back to a third party server (if the video content was embeded via a jsonp wisget etc.) ??
That's the point - it can do whatever you can do, all technical prerequisites are available (threads, background-requests, runtime-dynamic code etc).
Once the proper tools are available providing diverse standard functions, it will spread and be easier for non-developers.
Hixie answered your specific question, but I think you're missing a very important point: "Doesn't every major browser release leave less and less that Flash alone can do?" There are some things (not this one) that Flash can do that browsers aren't yet able to do. The present limitations dictate what you can do today, but they have little relevance to the long-term discussion.
