I still think they have a treasure trove of places to go with her. It's unexplored in the comics but I think Singer & co. need to expand.
1. It's sci-f at its max with telepathy gone wrong. A person is trapped inside another's body. We've seen the concept before with Lindsay Lohan in
Freaky Friday, etc.
2. Psylocke's is a story about being forced into a new racial & social cast. The character is forced to switch race, from white to Asian woman, and as a result, from majority to minority. Her understanding of her own society is put under scrutiny because, previously, she has enjoyed a privileged position, but, now, she is marginalized and discriminated for her colour, features, accents, etc.
3. Gender reassignment. I know it's strange, but, if they were to give audiences a chance, they could take X-Men where it's meant to be headed: towards accepting all sorts of people, no matter how different they are. Transgenders rarely get love in Hollywood and I think a CB movie about a transgender could begin to break that mold. Having Betsy be a man who turns into a woman is new territory for CB films.
4. Use Psylocke's butterfly symbol as a symbol of change & transformation.
5. Weave the stories and themes into an action-packed plot and you could have one of the coolest, most meaningful, X-Men ever. But of course, she must be a strong one in the end. She's a superhero after all and should be a symbol of strength for transgender & X-Men fans alike, perhaps teaching us to accept the card life dealth us and to bear through life, using everything you've got (in Psylocke's case, it's a ninja body & psychic abilities).