It would for sure be a concern - and to be fair I don't know a whole lot about the risk other than it seems to be a volatile area - but probably no more so than the hurricanes, tornados etc we see here in parts of the US. From what I understand, the seismic risk is greater along the fault lines which run through Wellington and the South Island, so if you're based in Auckland you're probably more worried about a volcano suddenly springing back to life than you are an earthquake!