I read somewhere that many websites are being recoded to remove their dependence on Javascript because the iPhone does not support it. Furthermore, Apple don't seem to see adding JS to the iPhone as a priority. I guess how this goes will depend upon how iPhone sales.
I also read somewhere else that a lot of the preparatory work to get Javascript running within Netsurf has been done - perhaps someone else could comment on if what's left to do could be a summer's worth of work for a student....
I noticed that WebWonder is going down the route of adding JavaScript to achieve various effects such as a "slideshow" feature. Of course, such things can be done fairly easily without JavaScript as I showed in: [link]
but I guess that the main RISC OS browser ought to be able to display what one of the main RISC OS website authoring packages is producing.