Info from thesims.com

Subject: Info from thesims.com July 7th 2014, 10:24 pm

In case anyone missed it there will be a CAS demo available for everyone soon. The post said late summer. But considering they have this month and next than the game is released it will probably be sometime late this month or august. Also there will be a live game play demo sometime within the next two weeks bare in mind its only going to be 15 mins. But it will help me make up my mind about a game I was super excited for now im kinda on the fence about. Here is the part of the post that confirms this:

"But let us show you this instead of just talking about it: The Sims 4 Create A Sim Demo will be available later this summer for absolutely everyone to play. We are currently rolling out an early trial experience and invitations are going out very soon to a limited number of fans to help us test it. After that, you’ll all get your hands on it and see firsthand the depth, personality and emotion that are part of your new Sims.

And another thing - we were thrilled that more than 1200 people came through our E3 demo room last month to see The Sims 4 in action, but we want all of you to see it as well. We’ll be releasing over 15 minutes of in-game Live Mode footage (with complete UI) in the next two weeks. We can’t wait to hear what you think."
Here is the link for the full post: http://www.thesims.com/news/whats-out-and-whats-in