Being able to snap fire heavy Weapons is going to mean a lot more to Tau than some armies. Rail rifles are more useful than they were when outflanking and Sniper Drone Teams are at least marginally more useful when coming on from reserve. Markerlights themselves will be able to hit on the move on occassion too.
Broadsides might risk not taking Advanced Stabilization and take multitrackers more now that they can snap fire.
And regrouping is now far easier in 6th Edition! there is no 6" rule. That is huge.