Earlier in the year, we reported on Corsair's exclusivity over Cherry MX RGB-based mechanical keyboards. The thing is, Razer develops their own switches and is not reliant on ZF Electronics (Cherry Corporation). The Razer BlackWidow Ultimate Chroma mechanical keyboard uses their own switches, not Cherry's, and is not subject to Corsair's exclusivity. The keyboard can be ordered now for $179.99 USD and will be available in September.
I contacted Razer and asked them about their technology. They could not provide any direct comparison between their design and the Cherry MX RGB, but they were able to add a few details to their offering. The BlackWidow Ultimate Chroma was designed with its LEDs positioned away from moving parts and lined up with the keycap imprint. The LEDs are pointed upward for brightness.
Razer will be providing developers with Chroma SDK, allowing games and applications to control the Chroma-enabled device lighting to assist or immerse their users. I say "Chroma-enabled device" rather than "Chroma keyboards", because they already have plans for mice and headsets with the same technology. At the very least, they expect that users will appreciate coordinated colors across their gaming peripherals.
The Razer BlackWidow Ultimate Chroma is available to order, for $179.99 USD ($199.99 CDN), and ships in September. A Chroma-enabled mouse, based on the DeathAdder design, and a Chroma-enabled headset, based on the Kraken model, are announced but do not yet have pricing or availability information.