Be aware though - Google has a system in place to prevent gaming the just-in queue. So if you push updates too frequently they won't appear in the list. I've had this happen with my app a few times.

It seems that 8 days is the minimum time between updates, to qualify for this "just-in" status. A few developers have reported this figure, and it's worked for me recently.

Release Early, Release Often - just not too early and not too often.