Like the man said, Wayne was performed by Richard Hunt, Wanda by Eren Ozker (both of whom are sadly no longer with us, both lost to AIDS). When Eren Ozker left for the U.S. after Season One, to get married, the act Wayne & Wanda was dropped, although Wayne put in a handful of appearances in Season Three (as a soloist and as the hero in two melodrama sketches with Piggy and Uncle Deadly) and was in the opening number of the Debbie Harry episode in Season Five. Wayne & Wanda last appeared together in the episode with Linda Lavin in Season Four (Wanda was played by Kathy Mullen) in which it was revealed that they had fallen upon hard times after being fired by Kermit, who after being guilt-tripped by them rehired them on the spot. He couldn't even remember why he fired them... until they started singing again, and he fired them a second time.
The larger picture in the link shows Wayne & Wanda as they were in the first season credits, but they only looked like that in one episode, the one with Connie Stevens. For the remainder of the season they looked like they do in the bottom picture.
The Wanda puppet was used in Season Two a few times, but with a silver wig. She was in a couple of At the Dance spots, voiced by Richard Hunt in the Julie Andrews episode and by Dave Goelz in the Jaye P. Morgan episode. Before that, she put in an appearance as (GASP!) the Newsman's girlfriend (!) in the Steve Martin episode (they're sitting in the back, and before she arrives I believe the Newsman can be seen checking his watch and looking around). But clearly, the puppet was intended to portray a different character. Hmm, maybe Wanda's lesser-cultured sister, who got a couple of appearances on the show thanks to her boyfriend the Newsman? Fun to speculate, anyway.
Here are some more pictures:
http://www.kermitage.com/html/characterindex/tms/characterwxyz.html
The picture of Wayne there is from the Debbie Harry episode.
Hope this has been helpful. That reminds me, I've been meaning for a long time to write a "Behind the Muppets" mini-doc on the private life of Wayne & Wanda- the story you haven't heard lol! Gotta get started on that, too. So many projects.
David "Gorgon Heap" Ebersole