Would that be possible? A sprint jumping mod would be sweet. It would allow free running/parkour stuff. I would really enjoy that.

People have been asking for this for months (myself included) and no one has rose to the challenge. I'm very sad.

http://skyrim.nexusmods.com/mods/19668

Still a work in progress but it's really good.

Thanks for the link! I'll check it out.
Also, does anyone know if there's an underwater combat mod out there yet?

I was able to get underwater combat working by changing the conditions that allow you to attack. There was one issue if I recall, that you cannot holster or unholster your weapon once you are in the water. This was quite a while ago and the updates to Skyrim broke it. It could be redone, but honestly since there is only slaughterfish underwater I found no need for the mod.