Canon announced today the creation of the world's first 120 MP sensor. Yes, you read that correctly-- 120 megapixels! It's an APS-H (1.3x crop) sensor, the same size used in Canon's flagship EOS-1D Mark IV DSLR (which currently only has 16 megapixels). No word from Canon about when or if this will ever be sold in a camera. Obviously, I'm joking with my title, because if this is ever released it would cost a small fortune.
I'm also not sure what the point would be? Here's the dirty truth about megapixels-- having more of them doesn't mean a thing if the lenses on your camera can't actually resolve that much detail. I doubt that Canon (or Nikon for that matter) has any lenses that can.
Not to mention that you would need a supercomputer to process the RAW files.
You can find more info about this monstrosity at DPReview or Canon USA.