Another one mentioned by WillardFilmore, using his W in ranged form will let you kill a ward before it stealths, even at level 1.
Ranged W buff does persist between forms. This probably isn't too practically useful in most situations, but if you happen to have a Frozen Mallet it'd be something worth keeping in mind.
His ranged E also gives vision. Situationally useful due to a longer duration, but the vision is very thin, the range isn't long, and the placement you want isn't always available due to angle. Ryokoseigo brought up the usefulness in dropping this on a creep camp just to Q jump to them more quickly while jungling.
The vision on Q is such a huge thing. I know I've been saying this a lot but I really anticipate some jaw-dropping plays by pro players w/ this guy.