Palmer as it turns out is in the movie, but not as Wonder Woman. Instead she plays Talia Ghul, daughter of longtime Batman nemesis Ra's al Ghul.
Gale has very little acting experience but at least she seems to have the screen presence to play the Amazonian warrior princess (it goes without saying that she's beautiful). Megan is 5'10" tall and 32 years old, and I'm happy to hear both of these stats. Wonder Woman should be played by a tall woman and someone about 30 years old instead of some 21 year old pixie.
For a couple more images see below.
And here's a closeup: