Got a little downtime at work so I drew up an idea I've had knocking about in my head about what the gauge cluster of a future car might look like. The discharge/regen gauge that some current electric cars have (like the electric SLS) is on the right track but it's just the beginning. More detail about where energy is going becomes important, while revs become irrelevant and temperatures become footnotes that a warning light will suffice for (for real this time).
Here's how I imagine the dash looking on a CX75-like supercar, say 5 years from now. It has a newer-technology (maybe dual-carbon?) but small-ish battery that offers maybe 150 miles of range, direct electric drive, a supercapacitor, and an aircraft APU.
Mechanical gauges would be dead by now, so this is a computerized dash. I still think an analog speedometer is useful, especially on the sporty car, so there's something like that on the right. In the middle is an advanced discharge/regen gauge, on the left are energy store levels, and along the bottom are the drive mode indicator and a space for indicator & warning symbols. It may seem a bit skeumorphic to reserve space for symbols, but I think the cluster will be more intuitive and easier to read at a glance if everything has its own place. "dynamic" info could be displayed just below the discharge/regen gauge and above the reserved bottom row. Maps, media, and other non-critical stuff would be better suited for a center-console display.
The regen/charge meter is pretty simple, a bar on the left means energy is being harvested from regen braking, a bar on the right means energy is being expended through the wheels. The exception is the APU, a bar on the left for that means that energy is being harvested from the turbine to charge the battery and/or supercap.
The very top bar is a cumulative gauge that works like today's simple discharge/regen gauges. The R-brake value is the automatic regen setting - how much energy harvesting you get when you lift off the accelerator (can't call it gas or throttle anymore!) 0 and it coasts like a bicycle, 5 and you get something similar to a high-compression ICE's engine braking at high revs, all the time. Technically more might be possible, but it wouldn't be very safe to allow this.
In this scenario the car is cruising the highway in electric-only mode, using very little energy, all from the battery. The car has drive modes D, N and R, accompanied by power modes E, H and P...those should all be easy enough to figure out
Next I'll post some more scenarios.