I can't name the last show that did well on Sunday at 10pm. Its a real garbage hour with not many viewers.
iirc thats what killed Farscape.
If SciFi wants to kill BSG because of its costs they may be doing the move to really kill the ratings to prove to fans they couldn't keep it and to tamp down the viewer outrage.
On the other hand, the Dresden Files, will, I believe, be the lead in to BSG so maybe they are hoping for some synergy.
Good thing I have tivo because they are going up against Dexter.
And no one messes with Dexter.