tk2d doesn't have a built in parallax system, as there are so many ways to do this in Unity. Eg. you can get parallax for free by using a perspective camera. Sometimes its more efficient to move the layers yourself, sometimes its cheaper to have multiple cameras, etc.
The parallax demo isn't part of the toolkit as its just meant to be one example of implementing it. I can't find a way to integrate it in such a way that its foolproof to the end user. Eg. in that example specifically, its not possible to modify the layer names from an editor script which makes it really hard to integrate seamlessly like the rest of the toolkit.
I'd love to add one to the toolkit, but I haven't yet found a nice solution I'd be happy to add.