As was mentioned earlier they haven't released much info for Summoner yet and it won't be in the beta at all, but is supposed to be ready at launch.
From the Loadstone..."When playing as a job, you will have access to both the actions of the base class as well as those of the job in question. You will also be able equip certain actions belonging to other classes. Job-specific actions are acquired by completing job quests.
Besides actions belonging to the base class, jobs also have access to actions from certain other classes. Below is a list indicating which class-specific actions are available to each job.
Paladin >>Marauder and Conjurer ~~~~ Bard >>Conjurer and Thaumaturge
Monk >>Lancer and Archer ~~~~ White Mage >>Gladiator and Pugilist
Warrior >>Gladiator and Pugilist ~~~~ Black Mage >>Pugilist and Archer
Dragoon >>Pugilist and Archer "
http://lodestone.finalfantasyxiv.com/pl/guide/armoury01.html
So basically there's not enough information available yet to fully answer.Depends on what classes it gets to draw other abilities from, which we don't know yet. It might be a good combo , but my guess is it probably end up being a mediocre pet job.If it ends up being "OP" then it'll get nerfed real quick. I'm anxiously awaiting more info on SMN myself ...hopefully E3 will have some news on it.
Edited, Jun 10th 2013 4:40pm by marsupialboy