The narrator for "The Lab of Tomorrow" reveals to be Super-Monkey from "Dial M for Monkey".
This was the first time that Super-Monkey from "Dial M for Monkey" is given the ability to speak the human language. And is voiced by Corey Burton rather than Frank Welker.
Production code is 411.
Dexter tries to give his lab to Mandark in the next final produced episode "2Geniuses 2Gether 4Ever".