Why use IC cans? Will there be insulation up in there? Will the cans be touching any framing?

No insulation, I was thinking of a mouse house possibly sometime in the future that I didn't know about. Aren't IC's about the same price as non?

I don't get the "mouse house" comment.

They are about the same cost, but sometimes trim and lamp selection are limited with ICs.

If the soffit is sealed it could get pretty hot in there. I'd use IC "just in case" or add some ventilation. 2" or 3" round eave vents aren't very obtrusive.

If the correct trims and lamps are used it shouldn't matter how hot it gets.

what I should say is it will not get any hotter than any other installation regardless of what cans are used.

Racer- In regards to the mice. I have seen mice build nests from shredded material. I could imagine a clump of this material in the soffit next to the light, which may cause a fire? Am I being paranoid?

I can't say. I would suspect there are more mice nests in attics than anywhere else. Soffits get real cold around here come fall.