Below are a number of social networks and groups that are actively discussing instructional design related issues:
 
Instructional Technology Forum http://it.coe.uga.edu/itforum/
 
Society for technical communication: SIG on the instructional design and learning: http://stcid.ehost.com/wp/
 
Ed Tech Talk: http://edtechtalk.com/
 
Cloudworks: http://cloudworks.ac.uk/
 
CP Square: http://cpsquare.org/
 
Educause constituent groups: http://www.educause.edu/cg
 
Scope: http://scope.bccampus.ca/