i am able to watch smooth webm and smooth ogv 360p html5 videos with fennec. google via youtube are throwing their weight behind webm.

As for rebuilding microb, this won't happen without breaking conversations or ovi maps with the voice guidance hack (which i love and use), so I can't see it happening.

So, apt-get purge it now, but you'll be back as soon as someone with an iphone laughs at you for not being able to watch a video.