[wp-hackers] Unique permalinks vs. unique post slugs

[RePost]

Eric Marden wrote:
> Well, I treat categories like buckets that content goes into, things like 'articles', 'announcements', 'media', etc. Something with semantic meaning. Tags are more topical and specific like 'Google','WordPress','open source'. This may or may not work for you, but by having the clear distinction, I can put posts in my buckets, but then tag them up with specifics that people can browse, via the archives, or tag clouds.
>   
In comparison, I treat categories as departments, and in fact include 
several categories in my menu.

While I now see the benefit of limiting posts to a single category, 
numerous posts would qualify for two or more categories. In that case, 
I'll probably create an additional, identical, tag for each category -- 
and then, what the heck, add a tag cloud to assist in navigation.

Is this proper form for WordPress and Google? If so, I'll go ahead with 
the plan.