Yes it and the A6 are helping to kill of the RISC OS platform (by that I mean OS+Hardware). At least unlike the A6 announcement R-Comp at least tell you it's an Athlon (the only processor mentioned on the A6 announcement is StrongARM).
I think it's ironic (in fact if it weren't so serious it'd be funny) - but the SpaceCube advert even says the following (apparently with a streight face) "Unlike PCcards and other solutions from the past, the RISCube runs full WindowsXP using real hardware, giving full speed/compatibility".
Let's turn that on it's head shall we ? SpaceCube can run RISC OS but like emulation from the past does *not* use real ARM hardware so therefore cannot offer the full speed or full compatibility of actual RISC OS hardware.