Hello, All --
An update to an app I had acquired on Amazon had been released in Google Play on November 17. So I'm waiting like a week now and still no update had come through from Amazon. I realize that Amazon isn't as fast releasing updates as Google Play, but still, a week seemed to be taking too long.
In the meantime, I believe it was around mid-week last, Amazon released an update to their Amazon App Store app, to correct some of the issues (multiple logins, etc.) stemming from the JB 4.2 upgrade.
Anyhow, to make a long story short, the Amazon App Store app update appeared to have turned off all my notifications. So here I was expecting to receive a notification for an update (actually two of them), but the notifications were turned off. I just happened to be playing around with the App Store app, when into settings, and discovered that all the notifications were unchecked. Re-checked them, and lo and behold, when I looked at my list of apps, three of them (including the two I had been waiting for) were tagged as having updates available.
So, just an FYI if you've installed the Amazon App Store app update (there was another one since then), be sure to check your notifications and make sure all is copacetic.