I have a friend with a woma that wobbles like a really bad spider. It's painful to watch, actually.

So yeah, some of them definitely do. But I haven't heard that "all womas wobble" the way I've heard that "all spiders wobble".

To be safe, I'd actually handle a couple of spiders at a show that have really obvious wobbles, so you know what it looks like? And then ask to handle the woma you want to buy. Better yet, ask to see it feed, since wobbles really show up when the animal is excited.