I want to know the answer to the following question:
At what event did Sony tell everyone about the CECH-4000?
All the background I'm provided with is that "In September 2012 at the Tokyo Game Show, Sony announced that a new, slimmer PS3 redesign (CECH-4000) was due for release in late 2012 and that it would be available with either a 250 GB or 500 GB hard drive.". Is that enough to answer the question?
Answer: yes