There is even something between an GPU - which can theoretically run everything, as can Mincecraft ;) - and ASIC. THis is called FPGA (Field Programmable Gate Array)

As the name says those things can be programmed, but different then the CPUs (hard to explain).
The FPGAs can only do the task they are programmed to do, you cannot run 2 different programs without reprogramming. But you can run any program, so you could first mine BTC and then Ether.
Because of their structure they are likely to be more speedy then CPUs, maybe even a bit faster (or more energy efficient) then GPUs, but you would have to write a programming first, for every single different FPGA. So it is not worth the trouble.