This might be another stupid question, but I see that when usingML v2.3 ML digital ISO, ISO 50 and 51200 are unlocked. Is this for both photo and movie, and on which models? I have the 550D and guess that due to the cropped sensor the noise would be pretty bad at 51200, but there are times when it might be useful, especially if shooting monochrome. Hope it's supported on the 550D. Likewise, ISO could be a real boon. On a recent holiday the light was so intense that it would have been great to use a lower ISO than experiment with exposure compensation and miss the shot.
It's for movie mode only, all cameras.