Can think of a few possibilities:
1 - the dev team might have just given up and decided to pull the plug from lack of support, and as a final fuck you all, recommended people go to microshits NSA unlocked...
2 - they might have sold out and decided to make a pay only version of TC
3 - I doubt its a NSL due to who the dev team are, they are no Lavabit, they of all people would be more likely to publish such an attempt to suppress them. If its state interference, it would more likely be more direct action against them that could trigger a reaction like this one.
4 - perhaps there actually is a bad enough security flaw in XP that makes TC vulnerable to attack, that ms is now refusing to fix due to it no longer supporting XP.
Brute force wise, Truecrypt has never been that resistant to a determined and resourced attacker. It does not employ either BCrypt or SCRYPT - its key stretching, rounds implementation are pretty crap. Elcomsoft say their forensic disk decryptor has the ability to recover keys from TrueCrypt volumes/partitions if a computer has been in hibernation while a container or partition had been loaded. And of course, it is also according to them, vulnerable to cold boot attacks and recovering keys from ram dumps.
see their ad here:
http://www.elcomsoft.com/efdd.htmlBut the more important thing is, Bitlocker is apparently just as vulnerable to these types of attacks. Even in saying that, I am going to go with number 4 for this reason. The timing of them quitting the scene and the fact that phase two of the Truecrypt audit had just kicked off focussing very much on implementation
http://istruecryptauditedyet.com/ The timing of the dev team quitting and phase one having just been completed and phase two of this audit kicking off I think somewhere in that is the missing clue to why.
