One of the bigger trends in the last few years has been the explosion of board wargames using miniatures, often pre-painted, instead of the traditional cardboard counters. A subplot has been a noticeable increase in the number of games using wooden blocks.
For a long time wargames have been defined in the popular mind with the hex-and-counter presentations pioneered by Avalon Hill and SPI in the 60s, 70s and 80s. A lot of wargame design theory revolved around the best way to use counters, how much information to include and how to show it.
The biggest advantage of counters is their ability to hold a lot of game information in a readily accessible format for play. Depending on how you count it, for example, an ASL Vehicle counter contains as much as two dozen bits of information. This allows for fairly complex game interactions. The drawback is, however, that the information is not presented in a form that is all that visually satisfying or enjoyable in a tactile sense. As I get older I also notice that it's a bit harder on the eyes, due to the very small print needed.
Block games could theoretically hold the same amount of information, although all the extent ones I'm aware of stay away from ASL's excesses and tend to be happy with showing half a dozen to a dozen bits of information. They look better and have a nice, satisfying feel to them. Wooden blocks have enjoyed a growth in popularity recently, although they are still the signature design point in Columbia's line of games. Several recent games have passed on the "fog-of-war" potential of block designs (Worthington Games, GMT's Ancients) , basically making the wooden blocks more solid versions of the old counters.
Miniatures are much more visually appealing, especially when painted, but they're inherently limited in their potential information content, which implies less detailed rules interactions or the use of separate data cards. Despite these drawbacks, this is the area of wargaming that's seen the most growth recently. Helping fuel that growth is the availability of inexpensive labor and manufacturing overseas, especially in China. Comparing the pricing of new games it doesn't seem that cardboard counters currently have a big cost advantage over miniatures or wooden blocks, but there's a clear preference for block and miniature games among players.
One thing that's less clear is whether this represents a temporary state of affairs that could easily change with another shift in economic factors or if this signals a more durable shift in player tastes.