Digital noise, this eternal ennemy of the photographer, is going to find a real opponent at its level: The 35mm Full Frame sensors of the new FF dSLR that just arrived on the market (or were there for a relatively longer time):
As a matter of fact, this is a considerable advantage of the big/large sensors which can make use of pixels whose size is proportionnelly bigger and so apter to capture light without using the ammplification devices (usually generating or increasing noise image defects).
This is a good reason to find it interesting to go and check the images présented by DPreview in its Sony Alpha 900 test. They compare some of these cameras at sensitivity settings between 50 and 6400 ISO.
Think about what any other SLR camera would do at the same settings (ISO 3200, no less!): More or less colored blurred blotches.