Yeah, Fortress had a lot of good ideas that we were looking at. We toyed with a way to render and enter unicode operator characters using angle tag notation a la "<circle-plus>". The whitespace idea is interesting but a little dangerous; I think we just need to be able to separate the syntax from the viewer and editor interactions.
There's an idea from Fortress (I think?) of squeezing out spaces to express tighter grouping -- that at least struck me as promising.