I've done some thinking about how best to address a growing concern I have and that is: "what happens when I don't need to enter abyssea anymore for endgame items?" I'll have loads of stones, tons of abyssites, atmas, curor etc. that, at the current moment, will have no foreseeable use. I like so many others have spent a great deal of time in abyssea, pushing towards the top of it's possibilities. I don't want to feel like all that effort went to waste.
Although I doubt the development team hasn't considered this scenario I felt I'd offer my two bits on possible uses of Abyssea Empyreal Paradox and I freely invite anyone else to offer their ideas as well. I'm not looking for arguments on why it won't work; I'm looking for positive feedback, alterations and ideas of how it can!

Abyssea – Empyreal Paradox:
It's a Paradox! Common rules don't apply here! So why not use that to our advantage and introduce popular “potential” HNM monsters here? By popular I mean consider Major Bosses from other Final Fantasy and Square Enix titles. For example:

Lavos! Where better to start than with a monster that completely annihilated an entire planet in a matter of minutes! I first played Chrono Trigger on the SNES and so it plucks of few heart strings for me when I consider taking my current character that I've spent a great deal of time on (years) and pitting him against one of the nastiest foes of my childhood. It's a paradox! When you fight Lavos in CT you're surrounded by a seeming void that transcends time why not dimensions and worlds too?! I'll leave creating a battlefield and potential drops to someone who's in authority. But a couple suggestion's I'll give would include: Rainbow Great Katana (Chrono's Ultimate weapon), A Sunstone (Potential Ammo or Neck piece) Ayla's Fist (Hand-to-hand weapon) Valkyrie (Marle's Final Crossbow) etc.

Doom Gaze: another very popular NM that's nostalgic for many long time Final Fantasy fans. It's been used in more than Final Fantasy VI. It was also put into the continuation of Final Fantasy IV on the Wii. Imagine my surprise when all of a sudden I ran into my old nemesis Doom Gaze. Instant Damage spamming because I knew he'd run away. When I think of XI game mechanics perhaps he could be another roaming NM like Turul; Except inside an Empyreal Arena. An ampithere that shows no mercy! Brought down to fight through using specific means. ex: Emotes or JA's. Runs away when you've done certain amounts of damage. A Race against time. Just food for thought.

Zeromus: Final Boss for FF IV. I think of Zeromus and I think of a Blue Mages Playground! NM spell learning? Yes, please and thank you!! Black Hole (AoE Full/multi buff removal) Big Bang (AoE Dark Damage?) Throw in Shadow Flare too. I doubt there's a BLU that doesn't want it from somewhere! Awesome spells, not too easy to learn, excellent uses. Many career BLU's I know hate not having 100% spell completion. This could offer a new level of a challenge to those who hold that sentiment. It's like a badge of honor separating them from abyssea burned BLU's.

Jenova: Well known Boss from VII. A little FF VII jenova music would go a long way here!

I could continue this list but, I think you catch my point. Having stated the above I'd also like to say, I totally respect that the development team has it's own ideas and plans for XI and may not see the need to pour resources into monsters that have already been created and used. I'll be the first to voice my appreciation for new creations.

However, I would just like to put it out there that as a long time fan of the FF franchise and Square Enix company. There's nothing like satiating a little bit of nostalgia. From the many posts I've read. I've seen many references to previous FF titles for ideas. While the game mechanics may not allow for many of the ideas presented; I personally feel that if any area of FFXI can feel the least restricted on potential nostalgia it's the final bosses and battles. I'm of the opinion nostalgia helps maintain player loyalty to your franchise.

Continuing on, when I look at the empyreal paradox zone I see it's connection to Al'Taieu. It seems to me that the addition of several side passages to various anomalies that lead to these potential battlefields would allow for both innumerable potential battles at the end game level as well as the continued use of atmas, traverser stones, curor, abyssites, etc. Well, I may have more details come to me as I think but for now that's my tidbit to offer. Here's to hoping I'm heard and not muted. Cheers!