That is nice idea. Unfortunately no. Once the recording starts it would go out of our hands at this time.
Once mobile devices can properly support WebRTC it would be possible to do that.
In our r31 however we do have an interesting parameter that you could test out and play around with (r31 is in developer preview release, will however be out officially soon).
Basically you can use orientation parameter to force specific layout of the recording - portrait or landscape.
You would add it to your HTML code as so:
Hope that helps :)