I'm still seeing way too many similarities between having multiple themed Sifter groups and Erik's team certification proposal. What is the putpose of Erik's idea? From what I gather it is to create selections of articles that have been reviewed by different groups. Each group would have its own rules on certification and on who they decide should be group members. These members would "certify" certain articles based upon those criteria and then a list of articles certified by any particular group would be automatically generated. Heck, this can be done right now without any change to the software so long as group members manually added articles to a list.
Sifter will be doing the /exact/ same thing except instead of compiling a list, particular article versions are automatically copied to a separate static website. There is no reason why a log of articles that have been uploaded by any particular Sifter group couldn't be generated and available at Wikipedia.
One of the great things, it was thought, about Sifter was that /no/ changes would have to be made to PediaWiki for it to work. But Erik wants to change the software anyway to do a very similar thing from within Wikipedia. So why not marry the two ideas and get the best of both worlds? Then when somebody visits a Wikipedia article that has been reviewed they will be able to see that at least a previous version had been reviewed. They would also be presented a link to a static copy of the certified version (with maybe a diff link so that the person can easily compare it with the current Wikipedia version). I don't think this is possible with the "hands-off Wikipedia" version of Sifter.
The trouble with Erik's certification idea is that people still can't rely on certified articles because somebody could completely replace a certified article with another version right after it is certified. Sifter versions are stable and therefore something that can be trusted (so long as you trust the quality and reputation of the Sifter member that certified the article and Sifter group that the member belongs to).
And as soon as there are a certain number of certified articles for any particular themed Sifter group, then a CD can be made of that selection -- no need to recheck each article for vandalism or rubbish that has been added since certification.
-- Daniel Mayer (aka mav)
PS I probably missed some points or even misrepresented Erik's certification idea. If this is the case, I apologize in advance and please do correct me Erik (I can't find your original email on this).