In many ways at this point NVS got what it wanted. If I were NVS I'd leave the current uncertainties with Mnta.
Now, down the road if Copaxane were to become an reality then NVS could look at them strictly from a financial standpoint.
What would not surprise me would be a scenario that if Teva is denied their Enox Anda, that BMY would step in and acquire Momenta. It would be a perfect deal considering their relationship with Sanofi.