Though now I wonder who the top dog is on the Shadowfell, and what sort of spells might they grant.
Shar might move to the Plane of Shadow (it's not Shadowfell, dammit! There's a perfectly good name for it already) and claim that position-her or Mask.
Apparently it's because they want devils to be more humanoid with demons bestial (and the 'loths to be insectile?). And with demons getting the "kill-crush-destroy" programming they don't fit in so well as seducers, especially if devils are all "bargain-trick-control". It damages past consistency, but they're slaughtering a lot of sacred cows for 4e.
We already have the devil equivalent of succubi-go look up erinyes in your Monster Manuals.
I'm thinking that with some of the other changes to how the planes and deities are looking, the most powerful beings on each plane are going to be at least deity-like. Asmodeus has made the shift, I'd expect the top Feywild beings (Oberon and Titania) to be able to grant divine spells, many of the demon lords already do, and most outer planes have a few resident gods. If you're capable of granting divine spells to your 'worshippers' then it's hard to distinguish you from a god, and i'd expect the top elemental lords to be able to do that.
But with all the elements converging into one big planar soup, I can't see there being no fewer than four greater deities on that same plane, especially when they're split into vendettas like Akadi/Grumber and Istishia/Kossuth are. We might just see a grand, overarching Elemental Lord arise from it all, if my guess that the existing lords are going to kill each other off or at least seriously weaken each other.
I have to echo the comments about elves and tieflings-the latter only make sense in a Planescape setting, and they are virtually all evil. Planetouched are better left as human subraces, in my opinion. Axe gnomes if you must, but don't replace them with tieflings.
Quite frankly, I'm starting to feel like WotC is dumbing down FR and making it more accessible, which I don't like at all. If you don't want to mess with all the complexities of the setting, you don't have to. Gloss over them in the campaigns. If you do want to mess with them, they're a ton of fun if that's your gig.