The NSA is apparently collecting and storing thirty petabytes of encrypted data per day and that's likely to include every iMessage sent worldwide. When quantum computers arrive, they will be able to decrypt that data and some estimates put that future uncomfortably close. Real breakthroughs in quantum computing have been made the last year or two.
It's good to see something is finally being done about that threat. I wouldn't count on the NSA being the only people with the data either - it's a goldmine and surely other governments are trying to gain access.