It would be cool if the Perun Flagship and that other unused Soviet helicopter (Twinblade, I think?) would appear as campaign exclusive units in the two finale missions for the Soviets, maybe Grumble too. And the Iron Fist. And the Voltmortar! (And even the kitchen sink!)
But seriously, for an all-in final assault by the Soviets, I'd love if they would utilize -everything- they got and more.
Also hopefully the Quickshifter for the Allies.