Quote from the11ama
This is true, but those pistons are supposed to work just like these, except for the lack of launching entities, just with different skins and a different name. The only thing that will happen at upgrade is that the current pistons will disappear. Everything else will still be in place, like circuits. all you have to do is add the new "pistons" in.
Do we actually KNOW that they will work exactly the same? the way pistons are powered currently is unlike any other block or whatever. I like the way it works, but I doubt that they will actually work the same way. for example the ability to power rows of pistons with just a line of redstone. I'm kindof doubting that my machines will work with these new pistons. From reading Jeb's twitters they seem totally nerfed. And yeah why delete the launch entities thing, thats one of the coolest things about this mod.
Hippo, we will always need you.