M5 Networks before being purchased by ShoreTel migrated from a Broadsoft platform (M6) to its own software. Sure, they had to hire 100 developers to replace the Broadsoft but still.
The biggest noise out of the Cloud Comm Alliance is that the licensing fees for the platform are like paying vigorish to a loanshark. RingCentral execs used that vig as a reason that some CCA members should migrate to the RC platform instead.
Nexogy must have been listening because they migrated to NetSapiens platform.
EMBRASE Consulting met with a couple of providers looking to get into the Hosted PBX game. Neither wanted to go the Broadsoft route due to the licensing "overhead".
Will this become a problem? Especially when Broadsoft makes little moves that puts the smaller HPBX players in the red-headed step-child corner. (Those moves include buying service providers, going wholesale (white-label), and helping bigger providers like Verizon to the detriment of the rest.)