I think the fJumpFallHeightMin and fJumpFallHeightMult gamesettings are what control it, though you'll have to wait for the CK and script effects to get it to work. Hopefully this game doesn't have that annoying invisible ledge bug Fallout had...
bumping this back up to see what people have done with jumping. I want a more platformer feel, but you apparently can't run and jump at the same time. My solution is to permanently increase player speed and jump height/movebase then disable run altogether (haven't figured out that last part just yet). This way the player is moving fast as jumping far all the time. If I could I'd rather running and jumping but it seems impossible.