I just watched the "evolution of ethernet speeds" presentation from NANOG meeting. There was a statement that there was "vendor secret sauce" in the 100G DWDM space. Yes, that is true, but:
There actually is a standard for 100G DWDM that has support from multiple router vendors. When you buy new gear, make sure your vendors support the above standard, so we can connect our routers over longer distances between vendors, without needing transponders.
We in the Deutsche Telecom Terastream project have Huawei, Cisco, Juniper and ALU routers that natively (DWDM colored interfaces in the routers) talk directly to each other over 1500 km amplified DWDM system (no transponders), and we can also talk from these routers interfaces to Cisco and ALU transponders if we want to.
https://jeffloughridge.wordpress.com/2013/10/16/peter-lothbergs-terastream-presentation-at-ripe-67/ if you want to know more about the project.
Next time you purchase 100G DWDM equipment, make sure you buy equipment that follows this standard to be certain that it interoperates to combat vendor "secret sauce".