Apple has announced iOS9 will be available in our 'Spring'.
iOS9 will bring new features and significant changes for how we manage iPads in schools with major improvements to both Configurator and MDM solutions. More details closer to the release date.
In preparation, you may wish to set your iPads to "Never Update Device" in Apple Configurator. This will prevent the devices updating automatically when you use Configurator the first time after Apple releases iOS9.
Then when you are ready to move your iPads to iOS9, you can change this setting back to "When Update Is Available".