Yoga yes, but Pilates uses a specific apparatus -- not unlike that CHuck Norris slidy thingamajig.
At first, I thought it was bullshit but as Steve said, with the right instructor, it's bitch. I'd say after a couple of classes you could probably replicate the moves with cables and weights, though it's a better workout when you're straining to do something that other people are doing and don't want to look like a wuss for being the first one to quit!