Just makes sense given the level of realism IC2 has reached, not to mention the level of freedom for the player thinking up all sorts of new designs and the level of control it would add to designs depending on heat and the rate at which they can be heated without having to resort to steam or nuclear power.
I know that hot coolant is supposed to be a lot hotter than steam for all intends and purposes, but looking at how radiators and climate control systems work and given the current base rate of the fermenter for instance I can think up several implementations within the same level of realism the mod has been designed around for the past few years.
Energy transfer without the lossness of cables over distance is just one simple example. Course you'd still experience loss by heating up but still.
Reheat left over Pahoehoe maybe?
Allow the seperation of the fermenter or blast furnace from the heaters is actually my main concern. That and the fact that a 2 dimensional system seems 1 dimensional with only hot-to-cold transfer.