This actually isn't a question specific to 2.5, but here goes because I'm curious anyway ...
I really love the "Hard Boss" FATEs that occasionally happen out in the fields, such as Lazy For You in The Shroud, It's Not Lupus in La Noscea, and Go! Go! Gorgimera! in Thanalan. I also know that those ones, with the massive bosses that take whole alliances to take down, are rare (I think there's only 4-5 in all in the entire world map right now). Is there any possibility that you might try adding more of those special FATE boss fights in the future? Maybe throw in some nifty minions to go with them like the existing ones have?