Truecrypt is still active in the sense that it is both something that can be downloaded and the last security audit showed that there aren't any major flaws. Are you referring to a different service, perhaps?

I don't remember the FBI being involved with TrueCrypt at all, but I don't know.

There was a case where the FBI wanted to force someone to divulge his (I think) TrueCrypt keys, which was found to be a fifth amendment issue, in favor of the defendant.

There's no known precedent for the use of the All Writs Act in the manner the FBI attempted to use it this time:

https://www.apple.com/pr/pdf/32_Law_Professors.pdf

"No court has ever issued a valid order that imposes an equivalent burden on a non-party. Our research has not found any case that uses the All Writs Act to require a third-party private entity to design and create new software. Some courts have compelled disclosure of already-existing information in cases where the All Writs Act is found applicable. In contrast, the order the government demands in this case would require substantial expenditures of time and talent above and beyond what is appropriate under the All Writs Act. This point is particularly alarming where Apple has made a deliberate decision to exclude the features that the government now demands."