If Tolkien wrote one more book what would you want it to be about?

[greyhavener]

I want another trilogy. Here's a rough outline:

Book one could follow the goings on in middle earth, life among the Hobbits, the kingdoms of Men: Aragorn and Arwen, Faramir and Eowyn, the Dwarves, the Elves who remained in middle earth giving details on everything that is hinted at in the Appendices, perhaps up until Sam departs.

Book two would begin when Bilbo, Frodo, and the elves board the ship at the Greyhavens. I'd like to see some interaction with the Maia. Perhaps some conflict among some ambitious Maia and the newly arrived heroes.
It would also deal with the passing of the races other than men. It would be sad. There could be the passing of the last Dwarf and we find out once and for all what happens to Dwarves when they die. The last Ent could fall asleep, the last Elf could board the last ship and sail into the West. Orcs and Goblins could enter into a war with one another and fight to the last creature. Hobbits become a more closed society, seldom venturing into the terretories of men and again become the stuff of legend.

Book Three would deal with the kingdoms of Men and the descendants of Gondor and Rohan would then be faced with a new evil originating from an unholy alliance of renegade Maia bred with women of the South...intelligent giants. Tom Bombadil would reappear (having never left his boundaries) and give some kind of aid. Hobbits would be forced out of hiding and into battle...