I bought all four of these movies when they first came out (yes, even Batman & Robin!!!) but I admit I'd quite like to have steelbook versions, particularly as I have the Chris Nolan trilogy all in steelbook cases too. The original releases all came on a single disc anyway so at least I can get rid of the originals without losing anything if I just own the steelbooks.
I'm getting annoyed at myself though for doing all this double-dipping of movies I already own on BD just to get a steelbook case. One out of three steelbooks tend to be crap anyway in my experience (cheap finish, lazy design, lack of internal art, etc.) so I'm trying to be a bit more conservative about which ones I buy. New movies in steelbooks are a given, e.g. The Hobbit, but I want to cut down on the double-dips for obvious reasons. I wouldn't really mind so much if these were remasters and/or had new extras or whatnot but in all cases they're just recycled versions of five years or older transfers. Must be easy money for the publishers as a way of getting rid of old surplus stock and we fall for it.