Awesome, we need all the help we can get to make more people aware about this since the mainstream media isn't covering it all. If only John Oliver did a take on this for us... :]
- author of this blog post
They claim that they need to keep it secret to maintain a strategic advantage as each of the countries trade off different provisions that could benefit or harm their economies. US Trade Rep says that if they make the draft texts public, then it will somehow effect their "game plan" against other nations.
This justification has become ever more dubious (or at the very least, extremely hypocritical) given the fact that the NSA has been spying on trade delegates and shares that information with the US Trade Rep. (Source: http://www.nytimes.com/2013/11/03/world/no-morsel-too-minusc...)