Canon 5D mk III announced. 22MP, up to 25,000 ISO (and that's the non-extended range!).
What makes this full-frame* camera (and its predecessors) interesting is that it gives pros and advanced amateurs more picture quality and more camera than almost anybody needs, and does it in a non-back-breaking package and at a (relatively) non-bank-breaking price, compared to the flagship models.
Canon says this model generally has a two-stop advantage in image quality over the Mark II model, which was no slouch. ISO 3200 looks like ISO800 used to! Dang. We've seen such before, but it's still amazing. With film or with lenses, a two-stop difference in sensitivity is followed by major downsides in quality (film) or weight/size/price (lenses). This two-stop advantage though, apart from a three-year wait, is essentially free and downside-free.
Imaging-Resource has a few interesting videos (well down on this page) of Canon's Chuck Westfall showing some of the many new features of the camera, for example this nice Quiet Mode:
... An interesting aspect is that sensors have now gotten so good that many are beginning to doubt who really needs a full-frame camera these days. In the early days, observers like Mike Reichman said that he considered smaller sensors (APS-C) a temporary format which would go away when full-frame sensor became affordable. But they have not become a lot more affordable for the last couple of years, and instead we are now seeing exchangable-lens cameras with really small sensors, like the Pentax Q and the Nikon 1, both of which have sensors much smaller than the M4/3 format, which is smaller than APS-C, which is smaller than full-frame. And we see a camera like the Fujifilm X10 which also has such a smallish sensor (smaller than M4/3, but bigger than that in pocket-cameras), yet is nearly a pocket-camera, and yet takes good quality images at ISO 3200, something which could only be approached by full-frame cameras just 4-5 years ago.
*Full-frame means that the sensor is large, the same size as traditional 35mm negatives, 24mm x 36mm, which is true of only a few and expensive cameras. The bigger the sensor, everything else being equal, the better quality, dynamic range, and sensitivity. (It also means that lenses need to be much bigger and expensive, though, especially if you want to really take advantage of the sharpness of modern digital imaging, which is higher than film.)