Cameos on the monitors before Jean Grey and Professor X are seen include quick shots of Domino, Cannonball and Magneto. Sabretooth is also seen once more in a clip from the original news cast in the beginning.
In the comic books, the Sentinels were introduced in X-Men (v1) #14. In addition, they were originally shown to be only slightly bigger than a normal human.
The creators of the show have altered the way Jubilee joined the X-Men. In the comic books, Jubilee met Dazzler, Storm, and Rogue in a shopping mall. In the issue, she made her way through Gateways portal back to the X-Men's base in the Australian Outback, as featured in Uncanny X-Men #244.
The poem quoted by Beast is The Unknown Eros by Coventry Patmore.
DEBUT: Cyclops, Wolverine, Storm, Rogue, Beast, Jubilee, Gambit, Jean Grey, Professor X, Robert Kelly, Morph, Henry Gyrich and the Sentinels.