One problem with O2 is the price. Richard may well want to get ahead of Netsurf, but Netsurf is free; O2 is £50? I'm certainly not going to pay £50 for a web browser that can't render pages written to HTML 4 standard and, more importantly today, XHTML. When Netsurf is complete, it will have complete support for HTML 4 and CSS, which O2 still doesn't have!
However, it's good to see Richard putting the effort in to see RISC OS get a decent web browser.