I love RISC OS - It's in my top three fave OSs (BeOS, MagiC, RISC-OS). Microshaft stole Acorn's Iconbar in 1995 for Win95, and Apple have just stolen in for MacOS X (the Dock).
I've just spent silly money updating my A5000 but it's well worth it - !2DWaves by Jan Vlietinck is the best computer program ever written for any computer!!! It's ace!!