Last night at 11PM British time (3PM PST or Midnight Central European Time) a chat event with Jenna Chalmers and Jonathan Knight was held at the official site. Another site, WorldSims already has the transcript available for you. Here's a small snippet, about the new lots and its interface, of the chat visited by over 250 people:

"We used lot numbers 50-80 for the new lots. The new larger neighborhood will be the first thing you see! No need to push any buttons or scroll anywhere. Its all right there in front of you. Downtown is the area that comes with the "Hot Date" expansion, "Old Town" are the community lots that come in "Unleashed""

We also get to know quite a lot of other things, like there won't be any leashes, but you will be able to get collars for your pets. Also, pets will dig into garbage or in the garden just to amuse themselves. So make sure they don't get bored! The Unleashed expansion pack will be released 23 September in the US, and early October in Europe. Visit this page at WorldSims to see the whole transcript.