I don't think SDC is going to rush to replace all this stuff at once. TNT can be repaired easily enough. That ride is both popular, reliable, and efficient. It would be stupid to get rid of it right now when there are so many other things to deal with.
Surely the FITH replacement is still in the works on some kind of timeline, even if it is delayed a couple years. It's hard to imagine SDC without either classic indoor attraction and nothing new to replace them. The PTB is aware of how popular these rides are, how important it is to have some indoor attractions that are open during Christmas, and the appeal of having some great thematic rides in the line-up that are beyond anything at SF/CF. I'm sure the crisis will delay funding a bit, but surely they will still eventually build a new FITH at least.
I really question SDC's cost benefit analysis sometimes. I know getting ROI out of an amusement park is a seriously tough puzzle much of the time, but a bit of preventative maintenance would have kept the classics going indefinitely. I really hope this rumor ends up being false and we get a few more seasons out of FITH until the economy recovers.
Also, am I missing something, or is the park being oddly quiet about Mystic River? Would love to see more teasers/updates.