I am not religious at all so I find the whole godparents thing a bit odd...but I am always up for a bit a speculation or guessing game
And as a preface to all those posts that said Prince Carl Philip or Princess Madeleine were too young to be godparents...Personally I would prefer a younger godparent, one who I could grow up with, maybe relate to a bit more, go to for advice...the idea of an "Uncle" Carl Philip or "Aunt" Madeleine as a potential mentor is very appealing...
I think:
Prince Carl Philip and Princess Madeleine (as the "couple" from Sweden)
Princess Martha-Louise
Princess Mathilde (perhaps over Princess Maxima, don't ask me why just a hunch)
The Reedtz-Thott's, Otto & Helle
Patricia Bailey and John Donaldson jnr.
Peter Varnoe (the Verbier guy, just to ensure ongoing vacations
)
A few wildcards:
Amber Petty - I doubt it though, but if you believe all the tabloids, Amber was apparantly very put out that she was snubbed as a choice for Christian's godparents (very petty) and I don't think Mary will restore the balance by making her godparent this time, but you just never know!
Princess Maxima and Prince Willem-Alexander - I have been known to be wrong on occassion
Caroline and Peter Heering - I am not sure about good friend, Caroline who is also lady-in-waitng would add to those responsibilities by being offered the godparent job...too involved I guess?
Some of Mary and Fred's other Danish friends that I not aware of...Mads Mikkelsen (I wish he was their friend) could be a good photo op (for me) with my two favourite Danes (Mary & Mads)