This provocative article raises many important issues that need to be addressed and in so doing will advance the fields of second language (L2) and third language (L3) acquisition in several important ways. Fundamental questions concerning multilingual development persist especially with respect to the role of Universal Grammar in this language learning process. This response article has a dual role: It first outlines those areas of agreement with the proposals made in this article and, second, it discusses those areas of the proposed model that need to be confronted in order to have the model evaluated as a fully viable one. [For "Microvariation in Multilingual Situations: The Importance of Property-by-Property Acquisition," see EJ1300541.]