Group array and group mirror modifier
If you group many objects, group array/mirror modifier would do mass array/mirror.
This could also be useful in animation of the array. For example, if one object is constrained to other in the group or to empty , rotation of the group could affect rotation of smaller parts .
5 Comments
Modifiers have been made to be applied to these types of objects : meshes, curves, surfaces, texts and lattices. (Groups are none of those because they're not even objects). However, you can achieve what you want by adding an array modifier to one of your objects, selecting your group while having the array-ed object as the active one and <kbd>Ctrl</kbd>+<kbd>L</kbd> Link the modifiers. And if you already have modifiers on some objects that you don't want to lose, you can enable the Copy attributes addon, select your objects the same way and <kbd>Ctrl</kbd>+<kbd>C</kbd> "Copy Selected Modifiers", select the array and click OK.
Technically, you can already do some of this. Create an instance of your group. That instance can be mirrored and you can have instanced duplicates if you use Dupligroups.
How can you make instance of the group ?
<kbd>Shift</kbd>+<kbd>A</kbd> > Group Instance
Thanks