IA 3 is already available in its 2nd edition to bring it up to date with new rules. Included of course are updated information for Elysian Drop Troops, Tau Battlesuits and Vehicles. There is a full video release by Forgeworld that you can see following the link below.
It works well that all the new Imperial Armour books are being updated, as it gets quite hard to validate a purchase of them when they are behind editions on rules.
here is your link