The Gamers' Temple has posted an interview with Jenna Chalmers from Maxis. She is a designer, and is currently working on The Sims Unleashed. There's quite some information about Unleashed in it, but not a whole lot of new things. However, there is a bit of an interesting tip in it:

"As far as pets go, dogs and cats require a lot of care in their first days home from the adoption center. While it may be tempting to buy several at once, for a smoother ride you may want to bring them home one at a time."

It also tells us that your Sims need quite some charisma to get their parrots talking. Get your sims ready for that, you can already train them for that now! Also, it seems that they've added skins they made for Create-A-Sim - which comes with The Sims Deluxe. However, that's all they say so we still don't know if that comes with this expansion pack too. Plus, there'll be some new music in Unleashed which, according to Jenna, is just great. We'll see about all that in September/October when this new expansion is due. The whole interview can be read from this page (it's a few pages long), all at the Gamers' Temple.