So, Alduin will return to "devour Tamriel." Loremasters, how literal can an event this apocalyptic be? A few possibilities occur to me initially:
1) Metaphorical world-eating
Alduin need not devour anyone or anything, but need only remove any form of resistance or risk to his presence in order to bring about this change. The "devouring" might represent some kind of terraforming that would result in a completely changed or renewed world.
2) Literal world-eating
Alduin will quite literally break the physical world as it is currently known, and slay or consume every living thing on it. This might be achieved over a period of time extending far beyond the point where civilisations of man and mer are no more. The literal "world breaking" might be a reduction of it to an utterly barren state, or a release of some kind of hostile energy related to Alduin and the Aedra/Deadra.
Am I trying to oversimplify the possible outcomes? Have I totally misinterpreted the devouring of a world by a hostile or apocalyptic spirit in the TES setting, or are there many more possibilities I haven't considered?