I'm thinking power failures could still be harmful, depending on your model and how cleanly the power turns back on. In my area, the power company is good at getting the power back on but it tends to come back on with a bang. We (our province) tend to blow up more appliances when the power comes back on than from oddball power surges, lightning or any other reason.
Now if the projector stays off after the power outage, probably a non issue. However, if the projector is designed to turn back on with the power, lamp and all, the lamp will take the full brunt of the hit.
This may not be as much of an issue for some people anbd I have no idea if even my projector's on/off functionality works this way after losing commercial power. It's still in the box but now that you have me thinking, I might take it out to do another test.
