Well, as I understand Sibelius is no more. Absorbed by Avid, probably making it into PT.
Presonus bought Notion, my strongest candidate if they would have implemented midi over rewire - so you could get a similar ease of use as Staff View in Sonar really is.We will probably see it integrated in Studio One 3.0 or something.
I've been able to rewire midi over with two instances of Reaper. Works just fine - so why no notation software implemented this is a mystery. I saw something about Sibelius, but sure if that really worked.
Just select the midi tracks you want and up comes staffs for it. It's a clever approach in Sonar for staff view. So getting that as easy with external notation software through rewire with midi - what a treat.