Mirantis is in the business of deploying a lot of OpenStack environments. And we see a great deal of demand for this type of feature. So we are completely for expending Cinder to support both block- and NAS-based storage. Having a single end point managing them will provide ability for storage platforms such as NetApp and Nexenta to offer both storage types from a single array, providing customers a significant cost savings.
Hope it will clear your doubt.