Erudites are much like wizards, but they cast from their entire spell-list spontaneously and can use psionic powers and feats, too. Their primary downside is that once they cast a spell (or manifest a power) that spell is 'locked in' for the day, and it's one of their limited number of powers they can choose to manifest until they rest.
And bards can be REALLY powerful, especially if you have lots of melee brutes in the party. +8 to all attacks and damage at level 6 isn't anything to sneeze at, especially if everyone allied with you gets it. 3 party-mates plus yourself, as well as 6 or so cohorts/pets racks up the damage PDQ. This is very much nice if everyone gets multiple attacks (especially with natural attacks; psywars, druids, animal companions, and totemists do this REALLY well). Say, bard 3/crusader 1/warblade 1/crusader 1 at ECL 6.