Canon just released some info about the 20Da. Apparently it's only available in Japan so far. From what I can tell...it's biggest difference is that is does not have the IR filter that all/most digital cameras have. Supposedly it's main use will be for astrophotography and possibly other long exposure uses. One thing that caught my attention was the hint that it might be able to use the LCD screen for live focusing with the mirror locked up. Doesn't sound like something that will be mass produced but interesting non-the-less.