I think the actuality of the situation will combine points of Joe's and Blackhawk's posts. IF (and I'd still call that a big "if") we get revised 121 rest rules, yes, that may result in a need for more staffing to keep the current route system unchanged. But, who says the current route system won't change? The supply and demand here is not inelastic- as Blackhawk pointed out, if the airlines costs go up, subsidies aside, the cost to the consumer will go up (it's needed to go up for at least the past decade anyway), and many people simply won't fly. That puts downward pressure on the airlines supply, so with less flights, we need less aircraft, and thus less staffing.
I'd say the chances of increased government subsidies to this industry are nil, at best. If anything, as the government budget crisis continues, I'd guess on a decline in EAS funding.
Are there a bunch of age 65 retirements coming? Sure. Is the sky falling due to that? Nope. Will the cost of buying an airline ticket go up? Yup (if nothing else due to the cost of fuel). Will work rules change? Maybe. Will entry requirements into the 121 field change? I'd say almost certainly yes.
All of these are pluses and minuses for pilot demand. I think the only thing we can all agree on is that the majors will be relatively unfazed by this, but whatever happens is going to affect the regionals the most.