I don't know, but the local sports bar has two projectors, and at least a dozen other displays, every one being a plasma, and they are on all day long, 7 days a week (I know the guys that installed all of this). They do turn them off for the 8 hours or whatever they are closed at night. This place has been around for about 15 years, and I don't remember ever seeing one plasma go out. They use Pioneers and Panasonics.
I've actually been behind one of those gargantuan (+100") plasmas. It was in the lobby of a Panasonic building, and is on all day. I took a pic of the backside of it, it had at least four fans, and I didn't feel any heat.
For full disclosure I've never owned a single flat panel ever, and my only display is a JVC projector. If I bought my first flat panel, there is no doubt whatsoever it would be a plasma. I mean, I wouldn't even look for one second into an LCD. So, yeah, maybe there is bias, but I put PQ as first priority, not saving $15 in electricity over the course of a year.
If you hang out in projector forums like I do, you will never ever see an LCD vs Projector thread. You WILL see plasma vs projector threads. There is a reason for this.
However for bryguy I'd probably just get an LCD, I dunno why. I mean, what else is there to really talk about here? I don't think I have anything else to offer right now.