Thursday, Apple released the minor updated iOS 7.0.4 to address issues with FaceTime and other problems. There was an issue with FaceTime where calls were failing for some users. The new update is supposed to fix that. Other issues were not specified by name.
The update applies from the iPhone 4 and up, the iPad 2 and newer as well as fourth and fifth generation iPod Touches. It can be downloaded from the Software Update section in the native Settings application.
For those with fourth generation iPod Touch, which cannot run iOS 7, Apple released iOS 6.1.5 to address the FaceTime issue.