I liked how you could lock things in Morrowind, that was pretty cool. How about a spell that isn't specifically for unlocking, but one that is for both unlocking and locking. Like "Ondusi's Locksmith" or something, a tap to lock, hold to unlock.
I could see that happening. Have a lock effect instead of two separate spells. That also free's up one of the 85 spell effects. Who knows, its hard to think up secondary effects for the lock spells, I could see them being merged happening.
As for water walking splitting the water...its possible I guess. Press to walk on top, hold to create a bubble that surrounds you as you walk under water? Maybe that's more for breathing under water...hmm. That's another tough one to figure out.
As for burdon, that could still be its own spell. Press to burdon on target, hold to cast a cone of burdon that slows all enemy movements infront of you, and charge to release an aoe burdon that halts all enemys around you in their tracks.
Along those lines, does anyone think we'll be able to move while we're casting these cones or aoe charged blasts? I could see us being able to move while shooting a fireball, maybe the ability to just turn slowly when you're casting the flamethrower, and finally you're stuck in place when you're charging.