Today EA opened up a new city in the Sims Online, called Betaville. This is a city that's more Sims 1 like, as jobs are existing, Sims get personality and even a free will. It seems Maxis is trying to make the Sims 1 go online, as many fans might have expected it to be in the first place. It's still a prototype city and the features may not be complete. Players can create a family of up to four Sims using a free will button in the Select a Sim screen. This family can then be placed in Betaville. See this post at Stratics for more information.

[Update 21:30] It seems there are some problems with the city. Although the information at Stratics says it should be possible to create a family even if you have three Sims in other cities already, people with three sims don't seem to be able to create the family:

"NOTE: We are aware of the current problem preventing people from creating Sims if they already have Sims in three other cities. We are working on this issue and hope to have it resolved very soon. Please refrain from reporting this problem so the bug board does not get too cluttered."