Some people still don't understand what 3rd Party refers to....anyway: Dart, Wander, Kat
I'm still looking forward to seeing Nariko and Sir Dan. Hopefully we get one of them and an unannounced character tomorrow.
I couldn't think of any 1st-party characters that I haven't already seen/been leaked, so I'm gonna post my 3rd-party picks anyway.
Kat from Gravity Rush
Death from Darksiders II (screw that non 3rd party rule)
Connor (to be honest I simply couldn't think of another first party char)