either emma or one the newbies but less likely emma. i could see the newbies being uncertain and thinkin they are on the wrong side and emma loves being a teacher so could see her wanting to join up wolvie's crew. magik, magneto and cyclops are oust by everyone so dont see them betraying each other, their all they have.
for those who say these are the traitors please, read avx and previous two years of uncanny x-men. wolvie and his crew turned their backs on their people when the going got too tough for them (which is totally out of character but whatev). kitty and magik are best friends but during all the drama she has been going through where was kitty when magik needed her? its suppose to be sisters before misters, but guess not when wolverine's involved :(