Having a way to simply and easily (without modifications or other hacks) get the position of a standard R/C servo would go a long way to making small bipeds much more affordable. So far it seems like the only way is to hack the servo (and connect to the pot), or do the current monitoring method (a much better method, but still not ideal).
Why exactly is the feedback required or needed for 'biped' control? Lets take a typical R/C servo application, rubber control on a model airplane. The command send to the servo via a continous PPM pulse width stream commands the servo to go to a specific angle and stop. When one sets up the initial servo/rubber linkage it is adjusted so that 0% command is equal to say +45 degree deflection and 100% command stick goes to -45 degree deflection, and 50% command is rubber neutral position. The servo itself is a self contained PID closed loop controller where the command sent to the servo is the desired setpoint. As long as one sets up the initial travel calibration for each biped moving servo controlled element, why go to the trouble and expense to build another redundant 'closed loop control' around the servo's control loop?