The joke about Mannoroth's Fury is how it affects Demonology and Destruction differently. That particular talent balancing happens with what spec they cared for last.
Non passive increment of radius for Hand of Gul'dan is terrible for Demonology (even if HoG doesn't receive any damage bonus), while passive effect for Destruction AoE is just OP.
And basically what you said about Cataclysm. I doubt the 'idea' of current 100-talents gets replaced completely.