Unbundling is a phenomenon that consists of dividing an existing software artifact into smaller ones. For example, mobile applications from well-known companies are being divided into simpler and more focused new ones. Despite its current importance, little is known or studied about unbundling or about how it relates to existing software engineering approaches, such as modularization. Consequently, recent cases points out that it has been performed unsystematically and arbitrarily. In this paper, our main goal is to present this novel and relevant concept and its challenges in the light of software engineering, exemplifying it with recent cases. We relate unbundling to standard software modularization, presenting the new motivations behind it, the resulting problems, and drawing perspectives for future support in the area.