The elephant in the room about Tether
Even an audit is not enough to convince all that they should trust the Tether's tokens.
Because there are many external risk factors. The elephant in the room are three-letter-agencies. They can do what they did to Liberty Reserve and BTC-E at any time. Maybe they are waiting it to grow more. Confiscating bank accounts is easy for them.
USDT tokens are backed with USD in bank accounts. There are thousands of other tokens backed by promises and fantasies. Deal with it.
For me there is no big difference between having audit and not having one. The main risk is from the governments, not from owners committing scam.
If Tether's management want to commit fraud or fractional banking - they will do it regardless of the audit. Because the audit contains information from the past, not from the future.