The reason I want to remove jumping is simply because, on a real battlefield, you don't see soldiers hopping around like rabbits, same for games, too, like ArmA 2 and Battlefield 3 (I think), and those games are renowned for being realistic, as well as awesome.
Vaulting is a quick and fast alternative to jumping, and it also looks awesome.
You should be able to still walk up 1 block high things, but you should be able to vault 2 block high structures, and it should be fast, too.
Jumping, although, should still be implemented. While sprinting, you will be able to do a long jump, to get across crevices or jump to other platforms.
I have been thinking of removing walking up 1 block high things altogether, and make players vault over that
Or while sprinting, you vault over it automatically without pressing space all the time.
Like all of my suggestions, this isn't that thought out, so forgive me for making it sloppy (I'm just saying anything that comes to mind, when it comes to suggestions.)