Steven Wilson already mixed for Marillion... but it was in stereo and it was for marillion.com which is widely regarded as one of the band's worst, sound-wise. SW didn't especially shine on this one, average work - I mean he certainly did his best with sub-par material, so that it was listenable... but far from PTree's output.
(At this point I have to say I really like .com !)
We all expect Brave and Misplaced CHildhood to come out in surround sound one day or another, but it might be another, a far, far away another day. Very far away. And I'm afraid Marillion's management couldn't care less about this kind of release. Now, I'd gladly be proven wrong, and buy any kind of surround release of these two albums, any day, anyhow.