Thinking about an ideal final tool:
It seems to me that what would be ideal for ESR is to have a standalone helper tool interfaced with the program, that will take the current video (regardless of what format it was recorded in), and do two things:
1. Convert it to desired format for actual use. Depending on what format the file was recorded in, this could be as simple as leaving the file as is, to converting it to multiple formats for different uses. In an ideal case, one would record the original using a lossless codec specialized for screen capture, and then convert to format for the desired end use. Common target uses would be youtube, email attachment, or a format suitable for web upload, like webm, mp4, flash.
2. Help user share final video. This could include some combination of email, upload to youtube, upload via ftp, prepare html web page for showing the video (using something like FlowPlayer).
As I see it, this is really a standalone tool, not something to be built into ESR itself. ESR already has a system for configuring 3rd party tools and invoking them, so the work their is already done.
Based on my preliminary investigation, it seems to me the best candidate backend commandline processor for this stuff is a combination of ffmpeg and avisynth. Unfortunately while ffmpeg can be used portable, avisynth has no such easy option, but is needed if one wants to be able to process arbitrary codec encodings.
So now what's left is to decide whether it's worth me (or someone else here) writing a custom tool for this, or whether ESR should simply recommend that users install some other 3rd party converter tool for this task -- god knows there are enough of them already.
If anyone feels like writing this tool, let me know -- I'd be happy to lead the cheers from the background.