In addition to this, a corporation could
sue a country for passing laws that negatively affect their profits. For example, in Australia all cigarette packets must be plain packaged, have large displayed health warnings and large graphic images of f'd up lungs/etc. This is no doubt negatively affecting the profits of tobacco companies, but they can't do anything about it right now. If the TPP passes, they'll be able to sue the absolute shit out of Australia in a secret court run and presided over by international corporations and be almost guaranteed to win.
If the idea of an international corporation being able to sue a country because a law infringes on their profits in a secret court, and then
force that country to change its laws to better suit that corporation doesn't scare the shit of you, then you have a hell of a lot of reading and thinking to do.
EDIT:
I read this the other day, seems fitting. It explains pretty much everything you need to know about the TPP and free trade in comic form.