Had a quick glance at lunch and Jpeg would work to an extent.
1. Use JPEG Fine
2. Optimum JPEG quality
3. D-Lighting set to high
4. Use aRGB instead of sRGB
5. Use Lightroom as non-destructing platform
I may be being really idiotic but when I open my RAW (NEF) file into CS6 it says layer 0 instead of background like it did in CS5?
I always have to flatten the image before saving to jpeg even though this is the only layer.
It's all in the viewing distance.
I've printed many 30x20" prints for people from my old 6mp (3008x2000) D40 with superb results. Ok press our nose against them they're not super sharp but you'll be surprised just how big you can print.