I still wonder what the fuck happened to that whole Monarch storyline they had going during Countdown and Countdown Arena, Captain Atom with the power of all 52 Captain Atoms, an army of the strongest versions of almost all of the heroes in the DC Universe set to invade the Prime DCU.
Of course Superman/boy Prime showing up and destroying everything put the kibosh on that, but I liked that concept a whole lot when it was happening, actually that's about the only cool thing that happened in Countdown come to think of it.
To me that would have been far more fulfilling than the mess that Final Crisis turned out to be. The thought of all of the potential match ups as that concept played out had me legitimately excited about Final Crisis since I made the assumption that's what it would turn out to be, of course DC sure showed me what I can get for anticipating.
Morrison had some neat ideas in Final Crisis, he does have his moments, The Multiverse being common knowledge to every inhabitant of the main DC universe, his very well done portrayl of the GLC and their role in the DCU, the effects of a God being reborn on Earth, etc...
Unfortunatly from what Morrison wrote, post FC, he intended it to be more of more of an experiment and testing the idea boundries of what could be accomplished in comics, which to me suits an elseworlds title rather than a "Major Crossover" and it sounds like Dido had a hand in a few elements of the finale despite Morrison taking all of the blame for the series.
Of course outside of Batman's death there hasn't even been much aknowlegment of the events that occured, so it doesn't seem to have had much effect, which in my opinion is a good thing since the majority of Final Crisis came across as fairly nonsenical, I know several aspects of it still have me scratching my head.