While interesting, I don't see how they make circuit theory more complete.

> The ideal memristor was initially and abstractly formulated as the flux–charge relationship: dΦ = M dq, (2) which, in order to be invertible, must have M defined either in terms of Φ, or q, or it must be a constant. The latter case coincides with the resistor, while if M is defined in terms of Φ ... [emphasis mine]

From my reading, this means if M is constant (like R,L,C are for "standard" components) it's just a resistor - not the miraculous "missing fourth."

Curious to get other perspectives on this.