I am SOOO happy about this:

The Sims 3 Copy Protection
March 26, 2009 06:10 AM
Hello everyone I wanted to share news with you regarding our copy protection plans for The Sims 3.
We’ll have more information for you as we get closer to launch about everything we’ll have to offer on TheSims3.com and The Sims 3 Store, but we have heard your requests over the past months and here is our plan for The Sims 3.
The game will have disc-based copy protection – there is a Serial Code just like The Sims 2. To play the game there will not be any online authentication needed.
We feel like this is a good, time-proven solution that makes it easy for you to play the game without DRM methods that feel overly invasive or leave you concerned about authorization server access in the distant future.

We’re really excited to bring you the game for the PC and Mac starting June 2, 2009. The extra time we’ve taken to polish the game has resulted in an even better game experience for you to enjoy and we can’t wait for you to see for yourself!
Thanks for your passion and your loyalty.
Rod Humble