The Sculpt Spell Feat (Complete Arcane) is another ability that emulates (to some degree)an Archmage power.
In defense of the original Archmage PrC, it did take some feat requirements to enter the class. The skill and caster requirements are irrelevant, however, since almost all wizards would have taken them anyway.
My preference for character customization is to use feats rather than PrCs. Some (many) PrCs could be boiled down to a small handful of abilities that could just as well have been feats. I hope that PF keeps PrCs to a minimum and provides lots of Feat choices instead.