Yes the iPad mini is powerful enough to handle Split View and other multitasking features found in iOS 9.
iOS 9 multitasking features include:
Split View - Allows you to use two apps simultaneously side-by-side.
Slide Over - Allows you to slide into a new app without leaving the app you're currently in.
Picture in Picture - Allows you to minimize FaceTime or video into the corner of your display so you can use an app at the same time.