Network distributed rendering
As a Ultimate user I am rendering huge resolutions and often multiple scenes on same project. Most of my work ends up in offset printing. This takes very long time, often too long. But I can't accept quality degradation.
If GPU assisted rendering is to complex to or impossible to implement please consider implementing distributed rendering. You already have nice queue manager in ultimate version. It is good starting point to develop distributed rendering on client-server basis.
In my disposal are multiple high end workstations and few Mac Pro boxes that I would gladly utilize to assist rendering in through local network. I am sure there are many buyers of Boxshot that would use this option an maybe attract some new customers.
This is great piece of software and I will use it with great satisfaction in years to come.