Hmm, I see what you mean. From the viewpoint of compatibility with OpenGL ES I guess the parameters should be in terms of bytes. This could potentially also allow interleaved arrays, as you say.
Perhaps this is one of the points still under discussion among the group putting together the spec; it’s a pity none of them are posting here… but if they’ve changed the parameters in Minefield (even if they’ve introduced bugs by so doing) then presumably the tide is turning in the direction of using bytes – which would seem to imply that they’ll have to add some way of creating hetrogenous arrays, as otherwise the change will just be confusing and unhelpful. I’ll be interesting to see what kind of API they come up with for that!