My vague recollection from previous discussion is that the FFP regulations were supposed to provide for audits of the sale of club services and assets to conflicted third parties (e.g. other companies owned by the club's owners) to ensure that fair market value had been paid.
There's already stuff along those lines in many other branches of law, esp. taxation so it's far from unprecedented.
I imagine it would be a long and difficult road to enforce a ruling along those lines, however, you would have to think it would be subject to appeal and argumentation.
When you consider that clubs already accept very large payments for services of completely indefinite value (e.g. shirt sponsorship) the waters get very, very muddy. Basically the FFP rules might be able to mitigate againste bankrolling, but you can't see how they will be able to completely prevent it.