Hi Clandestino,
Whether mechanical or electronic, rudder is just rudder, it's used for decrab and engine failures so no need to have sideslip protections as long as the pilot has some idea what he should be doing
It's a bit more complicated than that as DozyWannabe pointed out.
In the event of a total loss of electrical power to the flight control computers, the only way to keep the aircraft level will be by using slip. When was the last time anyone practiced that on Airbus?
Boeing 777 has cable connection to spoilers 4 and 11 to maintain wings level. 11.5.2
http://www.davi.ws/avionics/TheAvion...ook_Cap_11.pdf