Architectural modeling is an integral part of modern software development. In particular, diverse systems benefit from precise architectural models since similar components can often be reused between different system variants. However, during all phases of diverse system development, system variability has to be considered and modeled by appropriate means. Delta modeling is a language-independent approach for modeling system variability. A set of diverse systems is represented by a core system and a set of deltas specifying modifications to the core system. In this paper, we give a first sketch of how to apply delta modeling in MontiArc, an existing architecture description language, in order to obtain an integrated modeling language for architectural variability. The developed language, MontiArc, allows the modular modeling of variable software architectures and supports proactive as well as extractive product line development.