here is speculation: Luke is going to struggle mightily to kill a single Rancor (as preluded to in the snippet from Abyss)
Since Marek killed TONS of rancors, all without too much trouble, this will utterly destroy Star Wars continuity as we know it.
Now, if luke destroys the thing with a hand gesture, it will keep star wars continuining linearly, BUT...I can't see an author giving him that easy of a win, because they all want their fights to be interesting, not logical.
Then again, I don't know if it should quite count THAT much against Luke, as Bane was almost killed by some animal with nasty teeth and a tail on the Dxun Moon.
Uh no, Luke warned the Rancor that it shouldn't mess with him (Luke), implying that he'll win...easily.
VER MILD SPOILER ALERT!
Han and Leia promised Allana that they'd let her ride a tame Rancor if they go to Dathimor (sp?), and they're going to help Luke and Ben out, so maybe Luke will control the Rancor like Bane controlled that Rancor and Allana will ride it!
SPECULATION:
Coruscant subplot:
Was what Han/Leia and the jedi did legal? I mean, didn't jedi stealth X's ATTACK a GAS ship and sneak off of the planet with the prisoners? Given that, would this start yet another war?
And what about the mandos? How is Daala going to explain them?
Luke/Ben subplot:
Will their journey about finding out what turned Jacen to the dark side end? Or will it continue on Dathomir, since it was conveniently the last (I think) place that Jacen visited?
Will Vestara stay evil or be redeemed? She doesn't seem to be that bad, and the next book (I think) is called Allies, right?
What about the surviving sith tribe members? What will they do?