Not quite. For example, languages like Python typically have generative class definitions -- meaning that a class definition always creates a new type, with no existing object instances being objects of that class. In comparison, Common Lisp has provisions for adapting old instances to match a new definition of an already existing class, including lazy updates. Taken to extreme, this allows for such things as large on-disk object databases (since presumably you don't want to convert a billion objects on the disk the moment you add a field to a class).
The main difference is that Erlang is very strict about the kind of programs it will run (purely functional green-thread-esque processes and OO systems that utilize message passing and code that is modified must be swapped in/out at strictly defined points in program lifecycle), whereas CL is a fully mutable environment where modification can happen at any time during program lifecycle. Much more powerful, which comes with benefits as much as it comes with the amount of guns to blow your feet off with.
