I have the ZEN WA-100 on the olympus pt-ep03 for the epl2.
It's a great setup. You can use 3 different lens behind that same port and they all work great. I use the 9-18, the kit 14-42 and the 60mm. Now that I have the 60mm, I rarely used the 14-42 any more. The 60mm works great behind the dome. Obviously, the 9-18 works well as that's the lens it was designed for.
This is really a great setup for any of the olympus PEN housings. You can go from fairly wide (100 degree angle of view at 9mm) to macro without changing the port. Image quality is excellent.