RC car action just published an article showing the differences between the RTR SC10 and the RTR SC10RS

Here they are:

V2 shocks: Easier and quicker maintenance and filling. No need for special tools anymore for removing O-rings, and most importantly (Personally speaking, B4 shocks suck to refill)
a bleed screw. Much easier to Bleed them now

Hex hubs up front: The SC10RS now uses the same wheel in both front and rear

Water "Resistant" electronics: you can't submerge them or hose them off when they're dirty, but at least you can drive through the rain now

JConcepts rear tires: No big deal, considering they'll wear out.

and finially

new stronger more durable differential

4 big changes
1 (tires) not so important change