Last I checked Congress is skeptical so it'll be tough for them to pass. And in the current congressional environment it might back-burner itself for a long time as they bicker and fight over inane shit or derail it with unrelated legislation. It'll also be a last-ditch attempt for the rest of us to block the deal by writing into Congress.

But the biggest defense I've heard for the TPP is greater uniformity on Intellectual Property law, which is already complex enough as it is. But for companies here in the US there might be more relief to know they have a wider range of avenues to use to crack-down on individuals in Japan "stealing" their characters. The sort of shit you'd find in shovelware in popular cases.