Looks great... I personaly don't like the drive going out the back but thats partly because I just don't have that kind of space on my desk.
I'm also looking at doing this project but when I got the $ I'll go for the drive out the side instead. As one can see in other projects like that the CDRom will not fit entierly with the shape of the A1200 but I was thinking of using a slotin drive and that should make it less visible and also give it the right feeling of belonging in the unit (disks going in at the right, CD's at the left and no trays coming in or out at either end).
I will probably just use a custom 2.5"->2.5"->3-5" IDE cable so I don't have to use an IDE splitter or other IDE hardware.