I was bored and I decided to make a list of all the superstars (RAW, SD, ECW) not in the game, but listed on WWE.com, not including Divas.
RAW:
Armando Alejandro Estrada
Charlie Haas
Eugene
Hacksaw Jim Duggan
Jeff Hardy
Johnny (Spirit Squad)
JTG
Kenny (Spirit Squad)
Mikey (Spirit Squad)
Mitch (Spirit Squad)
Nicky (Spirit Squad)
Rob Conway
Robbie McAllister
Rory McAllister
Shad
Val Venis
Smackdown:
Brian Kendrick
Funaki
Idol Stevens
Jake
Jamie Noble
Jesse
Jimmy Wang Yang
K.C. James
Mike “The Miz” Mizanin
Montel Vontavious Porter
Paul London
Scotty 2 Hotty
Sylvan
Tatanka
ECW:
Al Snow
Balls Mahoney
Christopher W. Anderson
CM Punk
Danny Doring
Elijah Burke
Kevin Thorn
Little Guido Maritato
Matt Striker
Mike Knox
Rene Dupree
Sabu
Sandman
Shannon Moore
Stevie Richards
Sylvester Terkay
Terry Funk
Test
Tommy Dreamer
Tony Mamaluke
16 RAW, 14 SD, 20 ECW = 50 Superstars/Extremists not included.
And a little extra for you:
44 Superstars In Game – Lowest Overall: Trevor Murdoch (77) – Highest Overall: Kurt Angle (95)
16 Legends In Game – Lowest Overall: Jerry Lawler and Jim Neidhart (84) – Highest Overall: Hulk Hogan (93)