...which is really excellent news! It's a rather large step to a unified OS. ROL can now (or very soon) supply a version of RISC OS 4 to every hardware manufacturer, whilst remaining backwards compatible to the older machines.
It would be great if future builds of RO4, like RISC OS 4.5 for example, run natively on Iyonix hardware with perhaps some driver support from Castle. I suspect this will be the case