I'd pick Cyclops over Rogue, as well, as the high-profile victim, from a story-telling point of view, because the expectation would be to say "They'd never kill him! [pause] Right?". For better or worse, Rogue could be *plausibly* killed, if there seemed to be no more *obvious* storylines for her character, taking away from the drama of the plot. But Scott feels indispensible to the team AND the larger X-Men mythos, and it would geniunely keep readers excited and speculating about "will they? won't they?" as the race for a treatment goes on.