I needed a little time to ponder the information you provided on GW Teal taxonomy and the '95 DNA. If I understand correctly, one part of the DNA testing is consistent with the Eurasian and North American teals being separate species, while another part is consistent with their being races, or sub-species.
Several questions/issues come to mind. Has DNA study changed/advanced in the last 12 years so as to render the '95 results too dated for reliability?
If these two teals are the same species and regularly interbreed, would we not expect to find a blending of characteristics over time?
In general, when species interbreed, do they produce fertile offspring (horses and donkeys clearly do not)?
Does anyone know on what basis the European split of the teal was made - recognizable form, DNA study, or other?
Responding to Hector's argument for checklists based on "recognizable form," I think he makes a good case. So lead the charge - do an article for ABA Birding laying out your argument. If they won't respond, then use the contacts with the New England bird committees for state lists. New Englanders have led the country in many issues, why not for some stability and sensibility in our checklists.