In portable terms, emulation is the only affordable way for RISC OS users atm.
For instance, I am a student, who would pay £1000 for a laptop that does XP & Risc OS instead of £1500 on a RISC OS only box.
That and the fact that there hasn't been a successful RISC OS laptop since the A4!
As far as desktops are concerned, physical ARM machines (Iyonix/Omega...) are the best way as these give the stability of a single OS Machine, and with the added bonus that you can purchase a PC for a cheaper amount, allowing you to purchase two Computers instead of one.