New Frontiers in Discovery

Last Friday, I went and renewed by guardian ad litem certification.  One of the issues we discussed was new attacks on guardian ad litem opinions in discovery.  Below is a list of some of the new frontiers in discovery and attacking the opinions:
                                                
                                      (1). Subpoenas for notes from interviews
                                      (2). Depositions of guardian ad litem concerning basis of opinion
                                      (3). Designation of expert witness or alternate guardian ad litem to attack
                                             basis of opinion
                                      (4). Interrogatories and Requests for production of documents to GAL

I see these becoming more and more common in the near future.