They talked about this Wednesday on the radio. Apparently, they're reshooting some stuff.
Whedon was originally added on as like a supplemental guy to help add a little flare, then when Snyder stepped down they handed him the reigns. Probably won't make that big of a difference.
I was also very sorry to hear about Snyder's daughter. His wife was one of the producers, I think, and they both stepped down after that.