I think the psionic classes will be divided up as:
Psion (controller)
Psychic Warrior (defender)
Lurk/Soulknife (striker)
Ardent {looting the Divine Mind's auras} (leader)
Some powers are going to be called surges, vaguely based on the Wilder's Wild Surge. Psionic Focus will probably be the name of the Psychic Warrior's method of "marking" enemies to fill their defender role. Ego Whip, Id Insinuation, Psychic Crush, Mind Blast and the other former "attack modes" are probably the at will powers of the psion.
It's possible that the Monk also could be a psionic striker, since there's already 2 martial strikers.