Seriously (with mental ray in particular), what if a blackout did happen? I think you can pause a batch render, and continue from that point, but just doing a regular render, I think you have to start over each time.
Anyways, what do you know about this topic, and has that (a blackout) ever happened to you?
Also, it would be nice if Maya gave more information to the user while rendering, imo. For example, if they had a hot button key you could push to see the current progress of the rendered image while it is rendering (both in batch and regular rendering). Also, it would be nice to know what stage in the rendering process the renderer is doing and how much time it spends on each calculation.
I'm not sure how to find that out now, but how could you find out specifically how much time it took rendering caustics, final gather, GI, raytraced shadows, occlusion, motion blur, etc. So, if the renderer could provide a real time listing as well as a final summary of different elements of the render along with how much time it took to perform those tasks, that would really help.