Apple has released the beta of iOS 7.1 to developers.
iOS 7.1 beta, build 11D5099e, has the usual bug fixes and performance enhancements that come from such a build. But, as 9to5Mac points out, noticeable improvements include the ability to upload burst mode photos to Photo Stream and a dark keyboard option that can be accessed through the Accessibilities settings. Other tweaks include an auto HDR mode for the Camera and tweaked text in Notification Center.
The betas are available through the iOS Developer Center.