Thanks for your input: 

 * I don't want to compare plasmas to wave-particle duality, but to the fact that plasmas exhibit a wave aspect (that can be modelled with MHD), and a particle aspect (when an electric current passes through it, and MHD fails.) Sure, the electric current can be neglected in many models (especially when dealing with MHD and waves). But as soon as you get for example filamentation and double layers, then the electric current must be taken explicitly into account. 

 * We could link 'non-Maxwellian' to the Maxwell-Boltzmann distribution page, but it would be nice to express in a word or two, what this really means. In other words, how is it significant and what does it mean. 

 * True, double layers do not require a current, and are produced between any adjacent plasma regions with different properites. 

 * Plasma instabilities formed when an electric current flows through them can have their own characteristics. For example, fluids can produce a Kelvin-Helmholtz instability including plasmas; but pass an electic current through a plasma, and it can produce a diocotron instability which looks remarkably like a Kelvin-Helmholtz instability, but is produced in a different way and has unique characteristics. 

 * If you want to have a go at tidying up the table/page, please go ahead. I can provide you with some addition information if you want to contact me by email, details at   22:20, 2005 Jun 11 (GMT)