Megan Gale, an Australian model. Or 'super' model, now. Ha ha.
Puns aside, this looks to be pretty good casting. Well, aesthetically, Galactus knows whether she can act or not.
But she'll look good in the costume and, in many ways, that's all that really matters. The chances of Maggie Smith winning an Oscar for her layered turn as She-Hulk are probably around 7 to 1, and who likes those odds?
Ain't It Cool has pics of Miss Gale being a model, including some rude ones, so if you like looking at pictures of pretty ladies go here.
Source: (Ain't It Cool)