Yeah sounds like the Bluray only version will change aspect ratio's in the parts that were done in Imax style. One of the online stores has this (dark knight) for $42 but there's still postage on top of this. Warehouse has been having some deals lately which is all good.
With regards to Planet Earth- which has had mention as a reference disk- the BBC Uk version (5 disc) is supposedly shot at 1080p. I have read conflicting information as to whether to view this at 1080/60p or change the default setting and view it at 1080/25p due to it being shot at 1080/24 or 25.
I'm looking at getting that Planet Earth Bluray collection. In UK and NZ you score 5 discs in that pack, awesome. This came out at the movies as a highlights movie at 1 1/2 hours long but the bluray/DVD releases are all the 50 min shows. More content on the DVD packs with extra special features included, but HD on the Bluray.
With regards your question of frame rates, I'm sorry but you'll have to try on your gear. People can comment in general but really it all comes down to what settings work best on your equipment, which will have it's own strengths and weaknesses with how it treats the different input signals. I'm all for what works best for your eyes/ears and this may well be totally different from someone elses settings, especially if it was with different gear as well.