A common mistake made by Bonham-doubters is to think that because his hand patterns weren't all that complex or intricate, he wasn't very innovative. In the end, drumming isn't about doing advanced technical things, it's about playing the right beat, and making it sound exactly right for the music.
Having said that, his single-foot bass pedal technique was unheard of. He did really fast, intricate stuff with a single bass pedal, which kept his left foot free to do things with the hi-hat. He also did much to advance the science of getting a really heavy sound out of the drums. He was no slouch with his hand patterns, either, but Zep's sound didn't call for terribly intricate hi-hat work or crazy speed up top.