I hadn't heard about this app at all, so thanks to iDesignSound for bringing it to my attention! Musaico is "a new compositional paradigm consisting of integrated loop-based and timeline-based approaches", but despite all that it seems like an interesting way of working. You can mix up some loops for playing them like clips in Ableton, or assign them into traditional tracks. Once assigned to tracks these can then be made into their own loops and brought back into the clip launcher as Super-Clips.
The iPad version has AudioPaste, so it is easy to get your own material in. Both versions can make use of the iPod library to import other people's (non-DRM) songs for remixing.
Here's a demo of how the remixed Super-Clip loops can be grouped and played along with other samples in a fairly intuitive way.