Players Handbook 2 adds the following new items into the D&D 4th edition world:
Races:
Deva
Gnome
Goliath
Half-Orc
Shifter
Classes:
Avenger (Divine Striker)
Barbarian (Primal Striker)
Bard (Arcane Leader)
Druid (Primal Controller)
Invoker (Divine Controller)
Shaman (Primal Leader)
Sorcerer (Arcane Striker)
Warden (Primal Defender)
Paragon paths for all of the above classes are included, as well as racial paragon paths for all the new races and all the races of the first Player's Handbook. Racial paragon paths are described as an 'exemplar of a race's defining characteristics'.
Also included is additional rules for Backgrounds, new feats, new magic items and rituals and an appendix with rules updates and clarifications along with an updated glossary of keywords