What if Meryl is not being cast as Aslan but, instead being cast as Aslan's mom, because Aslan is the Son of the Emperor from overseas?  This idea keeps popping up in my thoughts over and over again, I figured I needed to say something now since I have not heard this idea from anyone yet. Aslan is still a Lion and is a young lion at the time of Magician's Nephew. (I realize a lot of people would consider this heresy since Narnia is primarily a Christian story, but, Greta is not a Christian whatever her background or upbringing may have been. I do not think she may realize all the implications of this. I do not think Greta is trying to do anything that bad, she is just trying to present it as she sees it.)

@eustace I guess I like this better than Ms. Streep being cast as Aslan, but it still feels very “non-canonical” to me.  
As far as I recall, the Emperor Beyond the Sea (i.e. God the Father) never actually appears in the Chronicles, just as he doesn’t personally “appear” in the New Testament - so having him/her show up in the movie would be unusual.  Also, in Professor Lewis’ Chronicles, I believe the Emperor is specifically called out as Aslan’s father, not his mother.

Posted by: @nebuchadnezzar

@eustace I guess I like this better than Ms. Streep being cast as Aslan, but it still feels very “non-canonical” to me.  
As far as I recall, the Emperor Beyond the Sea (i.e. God the Father) never actually appears in the Chronicles, just as he doesn’t personally “appear” in the New Testament - so having him/her show up in the movie would be unusual.  Also, in Professor Lewis’ Chronicles, I believe the Emperor is specifically called out as Aslan’s father, not his mother.

I can't remember an exact reference to the Emperor as Aslan's father offhand, but I'm pretty sure there is one somewhere in the books. In any case, Lewis was writing at a time when gender-neutral language was far less of a thing than it is today. If the Emperor was intended to be female, it's absolutely certain (s)he would have been called the Empress. (Jadis / the White Witch is referred to as Empress of Charn in MN, and indeed as Empress of the Lone Islands in LWW.)

Of course in the Bible, Jesus has a mother, who is highly revered in the Catholic and Orthodox traditions and to some extent in the Anglican tradition (I'm not sure what Lewis's views on her were), but even when she is referred to as the "Mother of God", nobody is suggesting she is meant to be a member of the Trinity! And although Aslan is intended as a fictional idea of what Jesus Christ might be like if he came in a different form to another world that needed saving, Lewis is not writing allegory and he doesn't stretch the parallels too far. There's not the slightest implication that Aslan was born to a virgin lioness, who was visited beforehand by an angel and told she was to bear the Son of the Emperor. (Let alone any scenes where the cub Aslan is visited by some Narnian equivalent of the shepherds or the three wise men... )

And plot-wise, too, there's no need for Aslan to have a mother, and I can't see that concept doing anything for the story other than making the Christian symbolism far more obscure and nebulous (possibly even more than making Aslan into a female Christ-figure would do). Like a lot of others here, I really do hope that the Meryl Streep rumour was wrong from the start. But we still don't know yet.

Posted by: @eustace

What if Meryl is not being cast as Aslan but, instead being cast as Aslan's mom, because Aslan is the Son of the Emperor from overseas? 

For me this would be just as bad, if not worse.  Because the same thing still lies at the heart of the issue, which is taking the source material and making it into something that it was never meant to be.  Personally Aslan's enigmatic compassion for Digory and his situation resonates with me as a reader exponentially more than some reason conjured up for the film could.  "Oh Aslan loves his mum too, hurray".  

Still keeping my fingers, hooves and tail crossed for Aunt Letty or something