Does Russound’s announced release of their Russound I/O, or “RIO” command protocol bring CasaTunes any closer to supporting Russound C-Series keypads?

No.  The RIO simplifies 3rd party integration with Russound products, however, it does not facilitate integration with the keypads.

Last fall (2009) when I purchased CasaTunes software, the word from David was that CasaTunes would soon (December?) issue an upgrade that would allow it to provide metadata in Russound C-Series MDK-C5 keypads.  Has this effort been shelved?  I have several customers with installed Russound C-Series systems that would install CasaTunes if the integration with their existing MDK-C5 keypads was included.

Brian, although the project has not been shelved we still do not have the information we need to complete this project.  Unfortunately, we have no ETA at this time.