[Update: my mistake, it is not about the DP1, it is about the SLR SD-14, which has a similar resolution. I found the link in the middle of an article about the DP1, and I didn't pay enough attention. But it is still about a similar Foveon sensor.]
We talked about the upcoming high-quality Sigma DP1. Here's an interesting test of it. According to this guy, it seems like it actually may have unrivaled image quality for the size of the camera, just like the intention was.
Interestingly, the actual resolution of the files is small by today's standards, "only" 5MP, but the thing is that normal sensors cheat, they have separate little sensor dots for each of the three colors and so they have to extrapolate for each color. The Foveon sensor the Sigma uses does not have that, so the natural resolution picks up more detail per 100 pixels. There's no extrapolation of data.