Wit sent this email to customers today:

  - If you have a paying subscription, you won’t be charged again and your instance(s) will remain private.
  - Your open instance(s) will remain open
  - If you have open instance(s) that you want to make private (for free), please wait for a few days until we roll out this feature.

I'm a paying customer and had plans to pay them significantly more (I am building an app that will be released in a few months that will heavily rely on it). Personally I'd rather see it stay a paid service since I want an SLA and support.

That said, Wit.ai is a great service, the team is friendly and responsive, and I congratulate them.