Possibly, at any rate, it looks like even if Tony survives he won't be his old self. Mental retardation, amnesia, advanced alzheimer's (as implied by the dream sequence), something like that, which would turn the show on its head, maybe moreso than if he dies. It could also meet Gandolfini's wish to basically play a different character the rest of the season, ala "Kevin Fennerty".
Gutsy move on Chase's part.