I think there should definitely be a place for opinion and commentary,
but when it comes to informational articles about game elements, the
writing should be as NPOV as possible.
An example for how to handle this might be what I have recently done
in the Nissa's Binding article (http://www.elanthipedia.com/wiki/Nissa
%27s_Binding). I segregated opinionated stuff into a 'commentary'
section.
On a larger scale there could also be a whole section of the
Elanthipedia for essays and other opinion/analysis pieces.
http://www.elanthipedia.com/wiki/User:Diarik Diarik has already
published a number of personal essays, so I do see these as a viable
resource as well, as long as they are linked from main articles and
clearly marked as opinion pieces.
But yes, in answer to your question, I believe the majority of our
content, relating to hard game data, should be in the neutral point of
view.
~Naeya