PS3 about 30% digital
PSVita 100% digital
PC hard to say, I don't have many new games, haven't bought much since I've got the PS3, but I think around 30% counting since 2005 everything pre that year is physical.
Had 100% physical UMD library for my PSP until I sold it, still have two unsold games I think GTA VCS and Talkman.
Edit. Not counting PS+ games.
So it is happening...PS4 preorder.
Greatness Awaits!