We are in the midst of our digitisation project (actually coming to a [hopefully temporary] end due to lack of funding) and it's already starting to become business as usual in my own practises. When we get new photographs accepted into the collection, I accession them all as per usual but now add them to the scanning list before putting them into storage, and will continue this as new items continue to appear. To me it makes sense to make it business as usual though - if the existing collection is digitised we might as well make new items follow the same pattern. This only applies to the photographs at the moment as they are among the more frequently used items in our collections; the other archives we hold will be digitised as required for now.
Plus, it's already business as usual for the objects we receive to be photographed before going to storage, so I'm working on getting the same processes in place for the archives!