berserker is already inclued into warrior/marauder.... some class/jobs we have in FF14 are a mix of other jobs.
like the conjurer that is a mix between white mage and geomancer. don't forget that the game at the start before they did add jobs was planned for have a large number of class....

(ref: http://www.google.fr/url?source=imgl...ATv1DsllHxK_TQ )

i dunno for the beastmaster, people tend to think that a jobs that need the pet for do anything will be a thing... i did play game like this in the past and in high level content whenever the pet was dying it was frustrating. the pathfinding trouble, latency in the execution of the order,....
it gonna be a pain for them. even wow didn't go this far into the pet jobs, if you look at the hunter, they had access to a tons of pet, but most of them have 2-3 skill max.

i dunno if beastmaster will come or must be bring to the game, but i feel jobs like dancer/samurai will be bring before it happend.