Is it possible to apply two different HIPS firewall policies on to two different NICs on the same machine? Anybody ever done anything similar?
No, you can't apply two different firewall policies, but you could try applying a single firewall policy with two different CAGs (no isolation) that would match each adapter individually. Each CAG would contain rules that would only be applied to that matched adapter.
I don't know if this would work for what you need it for though.