First of all, I freely admit I may be going way overboard with this notion, so feel free to shoot me down. My question is how scriptable or smart our money can get? For instance, can you have coins that look around themselves and say, "there's too many of us in this wallet," and abandon ship for the farthest empty wallet they can find?
Taxation of excessive wealth is one of those cases where an external (hence potentially untrusted) party imposes order on the monetary system. According to a recent IMF study, for instance (http://www.imf.org/external/pubs/ft/sdn/2014/sdn1402.pdf)
taxation of wealth promotes growth and prosperity for all. Right now, that happens as an external imposition on the owners of the money. Nobody likes taxes, and power can easily skew taxation systems to favour the wealthy. (Of course we know that NEVER happens!) But could the currency itself dislike its own concentration, and flee when it literally becomes too much?
I know this notion is somewhat similar to demurrage (hence, Freicoin) but in this case the currency does not depreciate, it simply moves of its own accord.