My personal preference is to stay away from TEST as development environment. TEST exists for the benefit of SOE, not the players. I think having a seperate forum (as now exists) should be sufficient. However, I think it will only take a few instances of getting "burnt" by having SOE change the code from TEST to LIVE to realize that its not worth the publishing effort.
I think DENMOM from eqtraders summed it up quite well.
http://mboards.eqtraders.com/phpBB2/viewtopic.php?t=12
And I realize that recipes, etc.. are a bit different from the interface itself, but in some respects the issues are the same.