I have BL3s up on the wall, about 15 degrees "behind" me, and 1.85 meters from the floor. In my room, placing them all the way at ceiling level would be way too high.
I had a sound engineer in my listening room, someone who has recorded and mixed some world artists, including Vladimir Ashkhenazy, and this engineer was much opposed to having my BL3s even at that height, saying I should place them on stands at the same relative angle. He felt the sound energy was hitting my ears at an unfavourable angle. I told him that the placement was optimized for movie surround, and to that he concurred - as that's where movie surround speakers are placed. His preference was dictated by the fact that he produces records with high-resolution, multi-channel playback.
So - for movies: yes, place them up on the wall, or suspended from the ceiling; if you will do most of your listening to music, don't go too high.
My BL3s remained where I placed them, as I use them 90% of the time for movies, and for that they're brilliant there.
The sound engineer's latest effort:
http://www.sa-cd.net/showreviews/5981