To date, I've referred folks to Wikipedia guidelines as a general
reference point and encouraged discussion.  We're a trade association
that functions as a roundtable for different industry sectors
(exchanges, buy and sell-side firms, and the vendor eco-system(s)
around them), so we're constantly moderating between conflicting views
(been an interesting learning experience to be able to voice three
conflicting views at the same time ;).  Accordingly, I've had the
liberty early on here to say "We make the final decision, period,
until you folks work out agreement amongst yourselves as to how to
resolve these issues".  Not sure that's really an applicable approach
here.  That said, some basics (NPOV (
http://en.wikipedia.org/wiki/
Wikipedia:Neutral_point_of_view), verifiable information (http://
en.wikipedia.org/wiki/Wikipedia:Verifiability), no personal attacks
(this is one where editors have to err on the side of caution), and no
copyright violations) seem to provide a framework for the conversation
at least.  I also found the "What wikipedia is and isn't" stuff to be
very useful -- see 
http://en.wikipedia.org/wiki/Wikipedia:What_Wikipedia_is_not
-- and would think that a similar approach would be helpful here to
get started.