MidNightRider - as a former 717 driver at Citrus I share and understand your concern about the future of AirTran. I firmly believe though that AT will survive and even thrive when compared to their competition.
I'll only address two of your points - you said AT’s business model is built on low oil prices however I'd say low operating costs, oil being one of them, would be more correct.
It is true that the oil prices have gone through the roof but it affects all airlines (except SWA right now) so their competitiveness in that aspect hasn’t changed that much. All other operating costs remain lower than the competition which means they shouldn’t have any trouble competing in their markets.
As far as Delta - they definitely are trying to protect their main hub at all costs however I think the NWA and Delta merger and especially the next step of integration will cost them more money than they anticipated. I also think the new Delta will focus on international flying even more than current Delta which should create some breathing room for AT. At least that's my take on it.
Ps. Hope the furlough plans never materialize for you and other citrusites.