Via Propellerheads Official Youtube channel:
Meet some of the developers bringing Rack Extension devices to Reason's rack! Rack Extensions allow 3rd party developers to bring their expertise, sounds, and inspiring workflow into Reason by merging some of the best elements of typical plugin expandability with the best elements of Reason's ongoing commitment to stability, efficiency, and musicality.
In this video you'll get a look at some of the first Rack Extensions to arrive in Reason's rack, hear direct from the developers themselves and, most importantly, see just how massive this expansion will be for your music.
Rack Extensions will be available un Reason 6.5 due for release in June. You'll be able to try and buy Rack Extensions at the new Prop Shop too.
A sneak preview of the soon to be released Zebra 2 update
We also got a look at their prototype Eurorack formant filter