In reply to AMS
You wrote "We've lost the prospect of new native hardware let's not lose the option of a vibrant developing OS as well"
RISC OS 4 has been continously developed since it's launch!
ROL have been adding both new front facing features and doing a lot of work to the backend of their branch of RISC OS. A version of this also runs on the only RISC OS hardware currently in production. Assuming another company comes along and wishes to use it,then more new hardware will could appear.
Castle released the Iyonix, a good successor to the Risc PC, but then didn't particularly do anything else to their branch of the OS. The only reason anything is happening to RO5 now is because of the ROOL initiative. If CTL had followed ROL's approach, RISC OS 5 could be much more feature rich than it currently is.