I don't have any Power Classes except the Noble and they did update that one to 3.5.
The classes in the book are:
* Alchemist
* Artificer
* Assassin
* Avenger (new class; basically like a chaotic-good paladin)
* Cabalist
* Charismatic (new class; dynamic divine caster)
* Crusader (new class; kind of like a non-spellcasting paladin)
* Eldritch Vampire (new class; arcane caster who absorbs spells from other casters - at higher levels he can "steal" spells)
* Exorcist
* Explorer
* Fool (I think this is "old" but it's not listed in the Power Classes section on Mongoose's site)
* Gladiator
* Hedge Wizard
* Knight
* Mercenary (new class; gets leadership bonuses and can make special knowledge checks to forgo using a feat he has to emulate the use of a feat possessed by an ally, plus other stuff)
* Noble
* Pirate
Each class also gets some associated feats, equipment, spells, and expanded skill descriptions.