UPDATE: According to the LBS (well... semilocal) who deals with Bionx, the SRAM 9 speed clusters are not compatable with the Bionx system, but an 8 speed cluster is. This would require a new chain, bar end shifter and the gear cluster. And, as a sidebar, these systems are on backlog with the new 350W hubs w/ Li-Ion batteries being out till late June.

I'd love to hear someone tell me this is all hogwash