no..
Steppers are steppers, servos are servos. You could home brew a true closed loop stepper system with lots of electronics exp.
Steppers are usually way behind servos in performance and speed this is also reflected in the price of steppers vs. servos. They were designed as a way to get close to servo position accuracy with out the added expense and complexity of a true closed loop system.
AC servo (brush-less) = true closed loop - highest performance - highest cost.
DC servo (brushed) = true closed loop - high performance - medium to high cost.
Stepper = open loop - moderate performance , can loose position - low to high cost.
Now i am not trying to say that steppers are junk, I have a couple of machines with them and they do great. I am just trying to say that they are what they are. I also have a couple of machines with ac servos and they stomp the steppers.
There is a company that makes a encoder feedback for steppers. It doesn't provide true closed loop feedback but it will tell mach to stop if a stepper has lost position.
Chad