The Sims 4 is only a few days away from being launched, with Electronic Arts making the PC requirements made available through the games FAQ page. Most will be surprised that you don't need a powerhouse gaming system to run it, with some pretty relaxed requirements. An Internet connection is only required for activation, so it's not an always-online mess like SimCity was.
You'll only need a "1.8 GHz Intel Core 2 Duo, AMD Athlon 64 Dual-Core 4000+ or equivalent (For computers using built-in graphics chipsets, the game requires 2.0 GHz Intel Core 2 Duo, 2.0 GHz AMD Turion 64 X2 TL-62 or equivalent)" for the CPU side of things, and 2GB of RAM minimum. 9GB of HDD space is required, with 1GB additional space needed for custom content and saved games.
A video card with at least 128MB of RAM is required, with Pixel Shader 3.0 support required - so we have NVIDIA GeForce 6600 or better, an ATI Radeon X1300 or better, or Intel's GMA X4500 or better. As you can see, the minimum PC requirements are very relaxed. The recommended specifications aren't that much more, with an Intel Core i5/AMD Athlon X4 or higher, 4GB of RAM, the same 9GB of HDD space, an NVIDIA GeForce GTX 650 or better and the 64-bit version of Windows 7, 8 or 8.1.