Does it expand (change aspect ratios) like in the Nolan films? There is a fair bit of grumbling among the videophile crowd who dislike the fact that the Blu-ray releases of TDK and TDKR change aspect ratios during the movie--it messes with their constant height theatre setups for cinemascope projection (some also complain because they're not getting the original aspect ratio in any case--IMAX 15/70 [often called "real IMAX"], has a 1.44:1 aspect ratio (quite close to the original Academy ratio of 1.37:1 that dominated films until about 1953 and the 1.33:1 ratio of a standard-def TV). On the Blu-ray, the aspect ratio changes from 2.40:1 for non-IMAX scenes to 1.78:1 (thus filling the screen--just as it did at the cinema).
In any event, I'm just curious if the aspect ratio changes in the IMAX presentations, but I would guess not, as I haven't seen it mentioned anywhere on the A/V fora I frequent and, by now, someone would have pointed it out.
There is almost surely an aspect ratio difference between the 2-D non-IMAX (which I'd expect to be 2.40:1, as it was in the last movie) and any IMAX presentation (2-D or 3-D). Skyfall was shown in 1:78:1 at IMAX screenings but in 2.40:1 at non-IMAX cinemas and home video releases. Makes for a few differences in framing the shots but they're likely unnoticed by most viewers in the absence of a side by side example.