Well, that is clearly not going to Happen. All of this was known in advance and Mueller has reportedly now resigned from his law firm to take on the SP duties full time. This looks like Rosenstein has made a biased selection in Mueller and now the almost limitless resources of a SP will be turned on Trump and all of his staff.
James L. Quarles III and Aaron Zebley resigned from Wilmerhale the same time as Mueller. They are assisting Mueller in this investigation.