Windows 7 SP1 is now available from Microsoft.

Windows 7 Service Pack 1 (SP1) is an important update that includes previously released security, performance, and stability updates for Windows 7. Installing SP1 helps keep Windows 7 up to date. For more information, see What's included in Windows 7 Service Pack 1 (SP1).

The recommended (and easiest) way to get SP1 is to turn on automatic updating in Windows Update in Control Panel, and wait for Windows 7
to notify you that SP1 is ready to install. It takes about 30 minutes
to install, and you'll need to restart your computer about halfway
through the installation.