I think there's room for a new grading company.
I don't think it will work if it's at all similar to the current ones. That "service" is a market that's totally overloaded, and has a pretty sound near monopoly as part of it.
A company with a different approach though, might have a small chance.
The two routes I see as possibly working
1) A fairly high end service with a high minimum price for grading, tiered pricing, but related to value rather than value and turnaround time. In other words, the grading takes as long as it takes. The company takes the time to get it right very nearly every time. The minimum charge would be fairly high, so it would be almost exclusively for more expensive cards.
Full scans taken and archived
A new sort of holder with space inside for a sheet with a detailed report on the grade etc.
That new holder could be customizable. I'm picturing something with gaskets like SGC, but not thin enough to cause problems, and available in different colors. Like red for Reds or Red Sox cards, white or gray for black bordered cards like 71T or 50 Drakes.
A solid database that's publicly available.
Enough knowledge to not need a further 3rd party checklist to be published before adding something. (If you're an expert, you're an expert right? )
2)Something along the lines of the Philatelic foundation, which can be donated to, and has an extensive library and reference collection.
http://www.philatelicfoundation.org/...ic-foundation/