At SimsCamp and the German community event at Gamescom we had ample time to test the upcoming expansion pack Into the Future. We did have to share computers but it was interesting to look over the shoulder of other players and watch what they were doing.
The new expansions comes with many new, futuristic objects and is a mix of World Adventures and a conventional expansion pack. Traveling to and from the future is probably based on the same (buggy) system as World Adventures and University Life.
Contrary to both the older expansions, your sims can stay in the future as long as they want. I did not find a possibility to leave a Sim in the future and travel back home though and it seems you can’t change the active family either while you’re in the future. What you can do is travel the future with only part of your household. Time in the present is stopped while your in the future