Only five of the 11 teams in F1 are in a financially secure position. Red Bull, Mercedes, Ferrari and McLaren are going nowhere, and Red Bull wouldn't allow their sister team Toro Rosso to fold.
The other six—Lotus, Force India, Williams, Sauber, Caterham and Marussia—are somewhat closer to the edge of oblivion.
Force India are part-owned by the huge Sahara Group, which probably makes them the safest of the six. Lotus are owned by a venture capital company and their debts are mainly to their shareholders, not banks, so they should be OK too (unless the owners get tired of losing money).
Sauber received a large investment from Russia last year, which secured their future for the short term, and Williams' financial statements show they appear to live within their means.
That leaves Caterham and Marussia. The former don't publish accounts in the UK (and if they publish in Malaysia I couldn't read it), but their owner, Tony Fernandes, has an estimated net worth of $625m, according to Forbes. They should be OK.
A check of Marussia's financial status presents an awful picture, but accounts are only available up to the end of 2012. According to The Times (subscription required, also reported by ESPN) their situation now is much rosier, after an investor wiped out their debts.
So we should have a 22-car grid in Australia.