Software-defined networking (SDN) receives plenty of hype. Now, the OpenDaylight project — backed by big vendors like Cisco Systems (NASDAQ:CSCO), IBM (NYSE:IBM), Microsoft (NASDAQ:MSFT) and VMware (NYSE:VMW) — hopes to turn all that SDN noise into real market innovation. The potential winners: software developers, channel partners and customers. Still, OpenDaylight — backed by The Linux Foundation — raises as many questions as it answers. Here’s why.