I noticed that the tags had changed, I had missed all of the discussion on meta.
I am still a little torn over the issues. Personally I think that has to be a good middle way.
Perhaps rather than editing the tags, we could edit questions to say for D6 or D7 or (5, 4 or 8). While I like the idea of a gradually updated wiki of answers reflecting the most relivant version of an answer with perhaps exceptions for different versions explained I don't think any community could be big or diligent enough to maintain that.
The current experience is (and this is not specific for DA), someone needs help with a problem and they post a question. They are really looking to find a solution to their problem. This will be specific to the version of the software which they are using. If someone posts an answer for a different version they have not had a good experience on the site and may not return.
So I think that we need to know the version of the software so that we can help users. If tags are not the answer ( and I do see the point with the Drupal-6 and drupal-7 tags polluting the site) then I think that amending the question with the version is the only way forward.
Those of us that answer questions can perhaps be a bit more verbose, and outline the solution, or at least what is different, for other versions of Drupal. But to give a specific answer I still think that the version number is required.