"OMGZORZBATMAN" is an internet term used to exspress over exaggarrated excitment or shock to the point of sarcasm. The phrase is not sarcastic in its self, but in the way it is exspressed.
Jerkass Joe: OMGZORZBATMAN! IS THAT A TUMOR!?
Sensible Susan: ...it's a zit you jerkass!
Jerkass Joe: Oh...my bad. :