I suppose this has been coming to a head for sometime, and became inevitable when Castle bought the licence from Pace. My own feeling, and it hasn't changed since Castle brought out Version 5, is that RiscOS Ltd will always struggle against a company that has its own hardware and software, plus the ability to still attract income from the legacy market.
Since Castle have decided to go their own way (thinking also of USB), I decided to stay with our RiscPCs (4) and use VA on our HP laptop. We are all very happy in this house, and are also happy with RiscOS Ltd, Simtec, STD, etc, who are still supporting us admirably. It is unfortunate that they may be affected by this fall out, and I for one think even less of Castle than I did before.