Fisch,
I've always been able to confirm an upgrade YOW-YVR. For this Sunday (with only 36 business class seats instead of 60), they said I could standby at the airport. And YVR-LAX is completely sold out in J. (Of course there are often no-shows, and I've only once gotten a confirmed upgrade, that on on a 7am LAX-YVR).
andrew