I was able to make the grenade missile move faster for the Raynor genade toss ability. I just can't figure out how to make the throw animation faster. It looks weird when he does a slow throw, then the grenade goes zooming out.
What you do is go into the Raynor actor and add an event that fires when the proper animation plays (in this case, the Spell animation; so you'd have it catch AnimPlay with a term of AnimName being Spell) and have it send the message Animation Set Timescale Absolute with Spell as the animation and [insert number here] as the animation speed. So if you want the animation to play 2x as fast, use 2.0 as the number.
I can throw up pics or a map with the changes if you need it =]