It wasn't so much her powers as it was just the visuals on them, somehow. Yeah, I can see both those guys coming back in future movies. It seemed a particularly abrupt way to off Cyclops anyway. Oh, and Phoenix too... those people just don't die...
The first appearance of Phoenix, bursting out of Jamaica Bay after crashing the shuttle, Uncanny X-Men #101 (October 1976, click for a larger version):
Dark Phonix shakes things up, Uncanny X-Men #135 (July 1980, click for larger version):
A panel from that issue (Dark Phoenix has just kicked everyone's... tail. Again, click for larger):
As you can see, she was a lot more theatrical in the comic, ironically.