I need to find out who the Canadian distributor is. See if I can petition them for a 3D Blu-ray release. Would solve the region issues for everyone.
Update: Does anyone know anything about the Australian Madman Entertainment release? Shows as region free on amazon.co.uk.
As far as I can tell, it hasn't had a formal US release. It shows as having a PG rating on filmratings.com http://www.filmratings.com/search.html?filmTitle=the+young+and+prodigious+t.s.+spivet&x=38&y=6, but that doesn't mean that the Downtown Independent can't show it uncut.
The Weinsteins are not likely to market this as a mainstream release, and certainly not to what would traditionally seem to be the target demographic ("family" film), which is why I think they would be successful in securing a PG-13 for it.
As a side note, the MF expletive is typically used to...
If the Weinsteins were to appeal an R rating, they'd probably succeed, citing examples like All the President's Men (11 uses of "fuck") and A Civil Action (3 uses of "fuck").