Jean Grey cameo in The Wolverine?

According to We got this covered, Famke Janssen flew over to Sydney recently, to the set for 'The Wolverine'. It's rumored that this is in fact for a cameo as he comic book movie character 'Jean Grey'!

This is a rather interesting find, as the actress had said that she was interested to appear as Jean Grey in Matthew Vaughn's X-Men: Days of Future Past.
Another reason for this to be strange news, is that this is a prequel, so in what way can she be included in the movie? You tell me.

Famke Janssen teases her return as Jean Grey

Patrick Stewart hinted that he may make a return as Professor X in the X-Men: First Class sequel 'X-Men: Days of future past', so why can't Jean Grey make a return; with the movie rumored to involve time travel and all?
Due to the rumor of time travel being involved, a lot of conversation has been going around about whether the old X-Men crew, will some how mingle with the current X-Men crew from First class.

When talking to MTV, she hinted her return:

 "One never knows," she teased. "Jean Grey, the Phoenix … she finds a way to reincarnate herself constantly, so one never knows."

Do you think she'll return as Jean, or is her future as dark as the Dark Phoenix?

Comment below.