Dont worry I had to read MPLS for Retards.
Is he implementing L3 MPLS VPNs or L2 VPNs?
I imagine its L3. What he is doing is extending the enterprise's Layer 3 domain across the service provider cloud to give the appearance of a private routed network that provides Layer 3, any-to-any connectivity across your enterprise.
MPLS supports QoS WAN optimization solutions, traffic engineering, IP VPNs, and more.
Just look on Cisco's website for explanations. Or you can buy the Ciscopress CCNP ISCW (or is it ICSW)...then again, is it IWCS...? :-) Who knows, its one of them. Read the chapter on MPLS and IP VPNs.
Victor