Does anyone know the current financial situations for these airlines? Both have extremely cheap fares from Newark to Las Vegas for December. I am wary, however, of booking so far in advance if one of these airlines might go under.

check with your credit card company. i think if you pay with that and the company goes under, they will refund your money.

You are CRAZY and driving me INSANE!

I've flown National twice, most recently a few weeks ago. They've been operating under bankruptcy for 2 years now, but flights are always book fairly solid, so I doubt you'd have anything to worry about. For travel to Vegas, they are my airline of choice. You may also want to check out their vacation packages. They own shares in a few hotels and at times have great package deals.
FYI, the west bound flight from Newark is usually delayed a bit, so if you use National, call ahead - still gets in close to on time, just a lot of killing time at Newark.

Actually, it's the other way around, I think. The casino/hotel groups own part of National.

Tomato Tomoto.

When I flew with them in Aug, the plane coming in was delayed and I had the chance to chat with the pilot for our flight while we waited. I know he said something to the effect of being partnered with them. You may be right, it could be the hotel's own part of the airline instead of the otherway around, it's been a while. Eitherway, we get good deals.