rogerd - 8:58 pm on Oct 31, 2012 (gmt 0)
I've seen tag pages outrank all individual posts for their keyword, so I wouldn't entirely dismiss their value. I suspect they work best when there is a body of content indexed under one tag. Also, I generally recommend not displaying entire posts but rather a modest snippet or excerpt.
Some SEOs always block category and tag pages. I like tags more than categories as categories have more of a tendency to duplicate the main blog pages. Tags tend to be more diverse and specific, at least the way I use them.