"Lot's (sic) of companies would refresh their branding after 5 or so years, maybe we should too."
In case you missed it, RISC OS 5 benefited from a full icon re-design four years ago, which gave it a structured and coherent appearance. The Iyonix branding was also new four years ago. I'm not sure when the cog appeared, but it must have been around that time too.
The cog is becoming a standard logo across the platform: throwing it away now would be extremely foolish and, given the politics, I suspect that any successor would be unlikely to gain such universal approval.
Finally, I'm with Druck on the last point: Richard, ignore the handful of whingers who haven't yet (AFAICT) demonstrated their design abilities.