Here is an article about Childress' first comments on the Vikes RB situation when he came over from Philly.
More waiting time for Moore
BY SEAN JENSEN
Pioneer Press
INDIANAPOLIS — Brad Childress didn't hand Mewelde Moore the starting running back job Friday. The new Vikings coach indicated that position would be addressed in the coming months.
Asked if he was comfortable with Moore handling the load at the position, Childress retracted his initial comment that the Vikings were "talent poor" at the position.
"Let me take that back," Childress said. "We don't have that many numbers. We just have two running backs there right now. (Adimchinobe) Echemandu is coming back; he's a little bit of an unknown. Mewelde did some good things. How many carries? We've done it a couple of different ways.
We could split them up; if there is somebody that comes through that we think can handle 20-25 carries, that's a way to go as well."
Childress cannot speak to suspended running back Onterrio Smith until May and said he would not make a decision on him until they meet.
http://www.twincities.com/mld/twincities/13957177.htm
I read this to mean that Childress is not wedded to RBBC and that if there is an RB that can handle the primary load, he would consider that route. When Taylor signed, Childress characterized Taylor as a "20 to 30 touch per game" RB. Whether Taylor can, in fact, hold up under such a load is a question because he doesn't have much history as a primary back. But this tells me that Childress will give Taylor the chance to take the load.
P.S. Note that Fason was not even mentioned in the article above.