We have released a Work on progress of Flamingo NXT 5. This is a new version that is integrated with many of the Rhino 5 rendering tools.
To download the latest version, go here:
http://wiki.mcneel.com/flamingo/5/primer
This WIP build will not replace the existing Flamingo NXT, but will add an additional Render engine to Rhino. This allows both Flamingo NXT and the new Flamingo NXT 5 WIP to both be used depending on which renderer is current.