A great article; thanks Chris & drobe! I'm also waiting in the hope that alpha channels will be introduced into RISC OS 5. This is one of the features I miss most from Select (I think it's also one of those features that would work best if it were available on all machines, so that sprites with alpha channels could be used for applications).
Having said that, I do think what Martin says about vector graphics is the way forward. RISC OS is in an ideal position to make the most of this kind of technology.
It's interesting to compare the article with the apple guidelines (also recently posted on OSnews.com):
And I always find the following site fascinating to compare against other systems: