While some of the comparisons are noteworthy, like the iPhone's metal and glass body vs. the plastic Pre, others just aren't. For instance, the Pre's 3.1-inch display vs. the iPhone's 3.5 inch screen. I don't know who's going to be dissuaded by 4-tenths of an inch. Plus, the Pre is a whole two grams heavier that the iPhone. Yowsa!
Of course, these stats are based on the current iPhone model. Rumors suggest that a new one will be introduced this summer. In any case, prepare for a fight.