Inherent in the word "instruction" is the root for "structure." Designing streamlined learning is about providing the tools and resources necessary for learners to internalize a framework (structure) on which to build their lifelong learning course (journey).
A succinct synopsis of Instructional Design (ID) may be viewed here: http://uniques.com/hybrids101/hybrids101/Design.html
In my limited view, designing instruction approaches the subject domain from the vantage point of the facilitator who will "instruct," whereas designing "learning" is from the vantage point of the learner's experience. With that said, a good Instructional Designer will take both needs into account (see link above).
Finally, as for PLEs and PLNs, the former serves as a tool for managing one's own learning. The latter becomes the platform for sharing with and in the learning of others. Though there may be rare exceptions, these environments require some guidance to form well (although I envision some apps appearing soon to aid in their development).
Netscape's founder announced a new web browser that is designed with the PLN in mind. As for PLEs, these will become increasingly automated as semantic pull technologies expand beyond the business sector to encompass educational needs.
