Advice from the DBK School of PR®:
If you had provided even a small update on Friday (and there MUST be something new that could be said since very little has come out since September 28th (actually much longer since that update had very little too), you would have achieved the original deadline for an update. Even if it wasn't all you intended, that would be secondary. The deadline would still have been met and you just say more will be coming in a few days, so we still get whatever it was you intended in short order.
Heck, some of the update can be provided with reference to what is coming a day or so later. For example, you might say on Friday, "We have been focused on a problem with bluetooth connections to a Mac. We have been testing several possible solutions to it and have hopeful results. However, before giving more detail on this, we want to continue testing over the weekend and review results on Monday. So we'll post more on Tuesday."
Then, if on Tuesday, unexpected work means you have to delay another day, it's not really a big deal.
Oh, there will always be people who still won't be happy. Can't help that until you ship, but in the meantime, you have people who naturally see this as one more example of missing an projected date. You may not be able to help missing shipping dates (none of us know what test results you have), but you sure can avoid missing these updates targets! Instead, everyone who gets upset about missed targets have just seen two more happen!
Just because you can't make them happy until you ship, there is no need to add to the frustration in these smaller ways in the meantime.
I have no problem with something unexpected delaying things. Heck, there could be family emergencies, etc, which simply must be dealt with. Which is why I advocate posting these updates in advance of the final hours so you're covered anyway.
Just how I do things. If I have to be somewhere at 8:00, I'll probably be there by 7:30. Or earlier. So it would take something really major to cause me to be late!
Meanwhile, just over 31 hours.