As I'm addicted to using Alt+Tab to switch between open application windows, you can imagine that in GNOME 3, where Alt+Tab only switches between grouped applications (read: two open terminal windows are grouped) is... a little different. You would go to that terminal application icon, and then a little downward arrow would indicate multiple windows had been grouped.
If you were to release Alt at that point, you would be presented with the window from that group you last opened.
I had been using the arrow keys to navigate to the window I actually wanted (down to expand group, left-and-right to select window), but now I have a new thing to get addicted to.
I just discovered this magic key-combo, so I'm pleasantly surprised and I didn't want to withhold all that positive energy from you; Alt+`