I suspect that the 2:1 split towards digital may be exceeded in this instance; if you wanted the game at launch, the digital pre-order was much more of a certain option than ordering online and hoping it arrives in Friday's post, and more convenient than trying to go to a games shop before or after work on Friday.
I can see that the market overall would still have people buying physical discs, especially where they're cheaper, but for launch sales I feel the digital option may be even more than two thirds of the total.