To be honest, Firebird is unlikely to see major overhauls, the most likely fix from Blizzard is to have the numbers bumped up. ie, damage per stacked increase to 500% or 600%.
At best, we can hope some of the more annoying issues can be resolved, and numbers bumped up. Completely redesign is unlikely, even though it should. Frankly, I will be happy with just the following:
(2) Set:
When you die, a meteor falls from the sky and revives you. This effect has a 60 second cooldown.
(4) Set:
Dealing Fire damage with one of your skills causes the enemy to take 5000% weapon damage as Fire per second for 3 seconds. This effect can be repeated a second and third time by different skills. If an enemy is burning due to three different skills simultaneously the enemy will Ignite, taking 15000% weapon damage per second until they die.
(6) Set:
Your fire damage is increased by 12000% and damage taken reduced by 60% as long as there is an enemy ignited.