Tank, DPS, I'm fine with either, since I play all kind of roles and jobs, provided we're actually getting SAM at all. I can list both pros and cons for addition to either role.

Only thing that would kill it for me would be the queue time for DPS if SAM is really introduced as DPS job. If DRK's addition managed to kill tank queue to THAT degree during HW's launch I dreaded thinking how much worse would it be for DPS queue.