Separation of duties: Development & Infrastructure

We maintain a development group and an infrastructure group. Because of geographic proximity, the developers have been responsible for the functionality of our web production platform.
As a result of other changes we are now implementing a joint responsibility for these systems between the two groups. Basically, we are looking for infrastructure to maintain the hardware, OS and services level software and configurations. Development will maintain the application packages they develop and the corresponding databases, etc.
This separation seems simple enough. However, in reality we have already run into a few bumps.

I am looking for input on the topic as well as policy templates that may be out there.