Hum, it looks like RCK did not have the time to implement this feature.
If it is still on the agenda, I would suggest doing it as they do on Ars Technica:
- show only a short line indicating the inclusion of a video, which when click, then expands the page to reveal it.
This has plenty of advantages:
- no slowdown when opening the page since the content is loaded only upon clicking
- keeps the thread compact
- does not bother people who do not want to see videos
I hope we eventually can have it.