This whole notion of aspects being the result of an attack is something I've been wrestling with since reading the books. The idea that a fire spell could burn a foe and slap an "On Fire!" aspect on them is one that I think should be in there someplace, but I don't want to just suddenly create a Maneuvers + Damage combo attack as that puts a LOT more power in to the hands of already very powerful characters.
I have toyed with the idea of a spell's Spin enabling an aspect, and if I did that I'd open that possibility for any action to do the same, effectively making a fragile aspect a boon to any Spin-producing roll (which really isn't a half-bad idea). Maybe, to help "balance" it out a bit more, an aspect generated in such a fashion cannot be tagged, but must be invoked (you have to spend a fate point, you don't get to do it for free) making it something that the PCs have to actually want to create (thus their story influence effort). Thoughts?