There were some last minute problems that I missed in my testing and we couldn't get resolved in time to get the upgrade done inside our window. Rather than start the upgrade and cause a potentially lengthy outage, we're going back to the drawing board.
Once we get the issues with the update resolved I will reschedule the downtime.
Sorry for the false alarm.
Better to have a false alarm than the alternative. To many times I see folks plow ahead anyway and just make a bigger mess. Much better to say "Stop, it's not going to work. It will be delayed." and get it right. </end IT rant>