Thanks for this advice. After reading your post, I decide to call United about a few flights coming up this month. Lo and behold, a few of my weekly LAS-ORD flights were indeed cancelled. The 1K desk was very helpful in putting me on another non-stop which was 4 hours earlier but fit into my schedule. When she told me that one of my confirmed upgrades on the original flight was not available on the rebooked one, I said "Really? Darn." and she immediately went into the inventory and found one for me. Very nice. Another thing happened. I am going ORD-SFO-SYD using a SWU but not yet upgraded on the international segments. Both domestic legs were changed but the international ones remained exactly the same. But in that process, the Wait-List changed from a PA-1 to some low-level one. She was surprised and put me back on the priority wait list. Is anyone familiar with this? Would be interested in knowing.