as far as streaming speed goes we've pretty much reached the maximum we'll ever see already. i predict maps will become harder to read ala hanzer/fanzhen/skystar style and this 'new age hard to read pattern' style will result in ar9.5 phasing out ar9. ar9 will be seen the same way as ar8 is seen now. This is further supported by how just about everyone is already picking up DT and getting comfortable with it even at very low ranks. These mapping techniques being used at higher BPM than we see them used at nowadays will be VERY hard to read at ar9 is just how I'd justify 9.5 taking prominence.
I also think this new breed of maps will cause people to finally lose interest in speed and go back to aim, and we'll end up with someone better than cookiezi because of it.
this is my prediction. in 10 years though, who knows where we'll be? this game is pretty timeless don't see it dying out ever with how the content is entirely community driven.