Originally Posted by Shikamaru
There was. Nolan originally had planned a few basic elements for 3 Batman films in his head. The films weren't fully layed out but he did have a basic idea of what he wanted to do (a simple basic outline like "Movie 1: Do Batman's origin with this villain", "Movie 2: Do the Joker with this character arc", "Movie 3: Do [insert villain] with Joker coming back", etc.). Heck, some speculate Nolan originally had plans for more than just 3 films since when he was asked about Robin, he said something among the lines of "Bale is still portraying a young Batman so Robin won't appear for a few more films" and he said this after TDK came out.
Regardless, everything or at least almost everything of the things Nolan originally planned for TDKR had to be scrapped because he didn't want to reuse the Joker to honor Heath (since we know the Joker was part of TDKR's original story). This lead to TDKR as we know it.
I personally wished he would've continued with his original idea for the third film as opposed to changing it completely since I am one of the many fans that was heavily dissapointed with TDKR. I believe the film to have contradicted and ignored many things from BB and TDK and to have been a sub-par Batman flick. That's just my opinion.
Nolan didnt have any ideas for the third movie. It was Goyer who said Joker probably would have returned in some fashion. Which probably would have been a very small role.
The only thing he said was the Robin thing, about him appearing "not for a few more films". This was at the time of TDK when he really didnt think he was gonna want to come back for any more movies or have any ideas left in him. So he probably assumed WB would just continue the franchise without him, since Bale had another left in his contract.
There were no plans at all. Only immediately after TDK, Goyer came up with the idea of Bane for a villain. Otherwise any other plan was just Goyer talking about how BEFORE tdk's script, Dent would have been scarred in the 3rd movie. Obviously that was changed when they wrote the script for Dark Knight.