The Sims 2 isn't out yet, but it looks like there are already plans for The Sims 3. Work on The Sims 2 was started shortly after The Sims 1 was released, and if Maxis does that again, that'd mean they'll start on The Sims 3 soon. A third version of the game can be expected now EA registered a new website domain, thesims3.com, until at least 2006. There's no website whatsoever there yet, but it looks like EA is just making sure that nobody else is able to register the domain before them. Of course nothing can be confirmed of The Sims 2 can be confirmed yet, as Maxis will first release The Sims 2, and then a bunch of expansions, before even announcing The Sims 3. Nevertheless it can be considered quite likely that a third game in the series will come some time, as it's a very popular game and people will still be missing some things in The Sims 2 for sure (even though it's a lot better than The Sims 1). We'll keep you updated as usual.

[Update 14:55] It turns out that EA even registered thesims4.com until thesims10.com. That would mean The Sims 3 isn't as definite as stated above, but EA is doing this just to protect their trademark, preventing others to capture those domains. Thanks to Tiger for that tip. Some of the domain records also point to ClubSim.net, which is currently the same as the front page of TheSims.com. If Maxis is ever going to do something else with that domain is not yet known, but that might happen in the future...

[Update 20:55] There are even more domains that EA registered recently. SimCity5.com to SimCity9.com have also been taken by Electronic Arts. These domains are also taken for the next couple of years. These domains also do not point to a website yet, but perhaps they will soon.