Keaton recently sat down to chat with Marc Maron on his WTF podcast, and he revealed he had pitched an origin story for his proposed third collaboration with Burton. "The guy who's doing them now, Chris Nolan, he's so talented, it's crazy. [Christian Bale] is so talented. It's so good." he enthused. "But I say that like I've seen them, and I actually haven't. I didn't even see much of the second one that I did."
"You look at where he went, which is exactly what I wanted to do when I was having meetings about the third one," he continued. "I said you want to see how this guy started. We've got a chance here to fix whatever we kind of maybe went off. This could be brilliant." But alas, his vision wasn't supported.
By this point, Burton had left the franchise, and Joel Schumacher was now on board, and as the actor simply says: "[He] didn't want to do it, so I didn't want to do it." And it was probably for the best as Keaton wisely saw that things weren't going to turn out well. "I could see that was going south," he stated.
And indeed, we got "Batman Forever" with Val Kilmer in the lead, and we all know how that turned out. And while we can dream of what a Keaton-led, Batman origin story would've looked like, at least we got two movies with the actor. Listen to his full interview with Marc Maron at the link above.