Not sure if this already exists, if it does I cant find it:
In geometry view, you can currently set the camera to the active camera and when you play the animation through it shows it in the geometry window very smoothly unlike in the realtime render window (I tend to pause the realtime renderer when working out animations and doing it entirely in geometry view to see how things are moving in real time).
It would be great to be able to render/export this animated geometry view for being able to quickly see what the animation will look like in real time and be able to comp a group of shots together in an external program (I use after effects) to get a feel for how a whole animation will come together very quickly. To do this I currently render my animations on the lowest possible settings but this still takes ages, whereas the geometry view can preview it almost in real time, I just want to be able to output it!
If there is already a better way, let me know!
Would be nice to be able to render the openGL view - great idea!
When that is said, does it also take long time to render if you have 'performance mode' active?
There is already a "preview" mode implemented where you can quickly render outpour animation. It can be accessed directly through the time line. There are also quality controls in the settings dialog (also located in the timeline).
I would use a screen record software like camtasia to catch the extra window geometry view.
There are tons of free tools that can handle this pretty well.