ryankenn,
The SD DVD is the only version available, it is your only option, its presented in 2:40:1.
This is a short quote from DVDTalk...
Presented in its original 2.40:1 aspect ratio and enhanced for 16x9 displays, The Dark Knight looks somewhat uneven from start to finish. It's worth noting that unlike the Blu-Ray release, this DVD does not change aspect ratios during the scenes filmed in IMAX format*---but since the majority of fans only caught this in regular theaters (myself included), it's certainly not a deal-breaker.
For the Blu-ray It tells you right on the back of the case that it is shot
with 2 formats...the original IMAX 1:78:1 & 2:40:1
There have also been many reviews of the Film before release.
All the Blu-ray versions are in this Format.
For me it was not distracting at all.It was very smooth,because it happened during a transition.
DVDFile
Rooster14,
I wanted to get the steelbook as well, but from past experience I decided not to.
They always seem to put the disk on top of each other on one side,so you have to take one disk out to get at the other one.Also the back has no label, its just a piece of paper.