In my recent post of IPv6 over MPLS, I have shown the high level design of serving IPv6 internet from existing MPLS cloud. The crucial advantage of using this type of design is to bypass IGP for IPv6. Definitely this design is having its own limitations and challenges but we are parallelly working on those problems also. Before moving ahead make sure you have better understanding of Penultimate Hop Popping (PHP) and basic concept of accessing internet in vrf.
I have added a document with full configuration and results of serving IPv6 internet in VRF Over IPv4 MPLS cloud.