The north American pokedex has 142 available Pokemon as of now. Currently unavailable in NA are:
Mew, Mewtwo, articuno, zapdos, moltres (legondarys will be available in special events in the future)
Mr mime (exclusive to Europe)
Kangaskahn(exclusive to Australia)
Farfetch'd (exclusive to asia and the pacific islands)
Ditto (not available anywhere yet, unclear if it can be hatched from an egg)
All other 142 are available in NA right now
Tauros is the NA region exclusive and it's unclear as of now if you can get other regional exclusives out of eggs