We debated long and hard with that article over the exact terminology. 

My understanding of what were able to decipher from the evidence provided was that "voiced by a female" is perhaps not necessarily the same as "female voice" and that "lion with mane" equals "male Lion" for all intents and purposes. But that's just my take.

Would it be better to have all of the cards more firmly stacked up on one side or the other,?

From a semantic clarity point-of-view, definitely. It's something of a brain melter trying to get all the data points to logically fit without going round in definitional loops.

From a filmmaking point of view however its absolutely impossible to say right now without understanding the intent and purpose of it, and the context within which it will be delivered..

Case in point - in the original version of Empire Strikes Back, the emperor is played by a woman, but voiced by a man, and has the eyes of a Monkey overlaid on her face.

If you told someone before hand that's what they were doing, fans would have had a meltdown. But on screen it all works. Arguably it's better than the Special Editions whereby they replaced the Emperor's scenes with Ian McDiarmid from Return of the Jedi.

Either way, i don't think the phrasing of your poll question is necessarily correct.

It's not "if Aslan is a Lioness, should she have a Mane?" 

But rather "If Aslan is a Male Lion, can he be voiced by a Female?

I am not sure why Meryl Streep was in talks to do Aslan (if the rumor was true).

It could be something to do with his singing Narnia into creation (in which case it might be a non-issue).

Meryl is very good at doing accents, perhaps she can perform a convincing wild lion voice that does not necessarily sound female. (Fran Walsh - Peter Jackson's wife - gave the scream / screech sound for the Nazguls in Peter Jackson's Lord of the Rings [see this behind the scenes video], I don't think the Nazgul sound female - so there is hope that Meryl could give a convincing Male Lion performance.)

I do not believe that it is confirmed yet that she is playing Aslan, but assuming she is - or a similar actress is - like you, I would rather have Aslan depicted physically as a male lion as per the books.

Posted by: @icarus

My understanding of what were able to decipher from the evidence provided was that "voiced by a female" is perhaps not necessarily the same as "female voice" and that "lion with mane" equals "male Lion" for all intents and purposes. But that's just my take.

I guess I just don't see the plausibility of getting a famous and charismatic performer like Meryl Streep to voice a main character and then have them disguise their voice. But I seem to remember them getting famous actors to voice the chipmunks in the live action Alvin and the Chipmunks movie and then made their voices unrecognizable, so I guess it's not unprecedented. (I haven't actually seen those movies; I'm just going by what I remember hearing.) 

It doesn't matter to me either way. If Aslan is female, I'm out.