I seem to recall reading somewhere that arcanist was going to be a pet class... I honestly think we should get arcanist and musketeer first, not just because I'm a huge musketeer fanboy (which I am) but because those of us who've been around since the start have been teased by them since the start.

Arcanists have even appeared in game from time to time. Urianger is one. Summoner seems fun, but Arcanist might fill the role you want (pet class) as well as being a mage.