5900 and 5930 have now updated firmware: R2416. This is a major new release for both platforms.
Take a look at the release notes, since there are many enhancements for both platforms.
For the 5900, this release includes the new IRF3 system, which is referred to as Enhanced IRF. You can now have 2x 5900 switches as Controlling Bridges (CB) and up to 30x 5700 switches as Port Extenders (PEX) and this will operate as a single logical device.
The 5900CP now has support for link-aggregation of native FC interfaces (like a Brocade FC Trunk), this is called a SAN-Aggregation interface.
For the 5930, this release includes integration with VMWare NSX, since the code includes an OVSDB agent, which can be used to manage the VXLAN tunnels.