.The French at DCNS seem to feel ready for experiments. The SMX-25 concept appeared in the internet a few days ago and is about a coastal waters submarine with an extreme surface speed.
109 meters submarine, 2850 tons conceived to operate in short depth (100m max.), would have a speed of only 10 kts in depth but 38 kts at surface. Fitted out with some torpedoes but mainly anti-ship missiles, and unnamed helicopters. Kind of a light stealth frigate / submarine mix.
I'm not sure what this surface speed may be good for (same mystery as with the LCS), and it reminds me a lot of the Engelmann Boot VS-5 (which were not actual submarines, though).
We might see more about it on the Euronaval 2010 exhibition.