JD posted the first stills of Woodley as MJ on the previous page. I really don't see what the big deal about her is. Kirsten Dunst wasn't exactly the knockout MJ was supposed to be either (and I say this as a big Kirsten fan).
MJ 616 is supposed to be the hot supermodel with more to her than meets the eye (that's why Peter falls in love with her as Trekker mentioned) but it's quite clear from the casting that they don't intend Woodley to be 616 MJ. I get even more of an Ultimate Spider-Man feel from this film than I did the original.
I googled the actress in question, and my first thought was "You're f-ing kidding me." And no, I'm not talking about how the actress looks or whether she's suitable for the part. I'm talking about all these guys who are saying she's plain looking.