For things like SpellCraft to determine the spell before it is cast, no.
For things like SpellCraft to determine the spell after it is cast, maybe. If the spell has visible unique effects, yes. If the spell has non-visible effect, no (at least in my game). If the spell has non-unique visible effects, it depends (e.g. an illusion of a Fireball with no components would look like a Fireball and would fool practically everyone watching it).
For things like a Ready action, according to RAW, yes. In my game, no. I have a problem with a Wizard screwing up his face and the Archer always absolutely knowing that he is casting a spell, even though there are no components to definitively indicate it.