@ Meddler, any thoughts on Varus?

Just out of curiosity. While he did receive a bit of love during the ADC update, I don't think it was really enough for him. The point I'm most interested in right now, is wondering if any love can be shown towards his passive? For such a 'high risk', the reward feels quite low. 40% isn't really much for killing an enemy champion, especially considering it's his only steroid. Would it be possible to bump this up, maybe make it scaling throughout the game? While I am aware Varus isn't designed as a late game hyper carry, even a 60% AS boost would feel much more appreciable.