Not the interconnects, but the links themselves. MCI is using Cisco hardware in their POPs. The IRR would be a good resource of information on how things are connected. Sprint does not register aut-num objects. Sean says that it's work.
Sprint does register some information.
The Sprint NAP's NSS router will be retired with a 7500 sometime soon. Moving to the new network has been a priority for those sites that generate lots of tinigrams. MCI and Sprint have not done alot of this type of analysis. Reproduction with attribution granted.