I've updated to Xcode 6 beta 3 and see that the [+ = -] buttons in the storyboard corner are gone. Is there a way for me to zoom in and out on view controllers within a storyboard in Xcode 6?
You can zoom the storyboard by double-click canvas or using top-menu(Editor > Canvas > Zoom).
Alternatively: Right click blank space on canvas and choose zoom level (allows to zoom out further than double click)

If you have a magic trackpad (external or embedded in the macbook) you can also pinch to zoom... It sounds quite obvious, but I've just discovered it.
double cick is best for zooming IN and OUT... just do a DOUBLE CLICK in the story board in Xcode 6
These keyboard shortcuts are working for me:
Zoom out:
⇧ ⌥ ⌘ {
Zoom in:
⇧ ⌥ ⌘ }
Your mileage may vary.
In order to zoom in or zoom out using a mouse just hold alt
(⌥) and scroll.
Easiest way is to RIGHT CLICK on the canvas, and zooming options will pop up
In Xcode7.0 Beta zooming the View Controller window requires shortcut keys: command + '+' and command + '-'
You can also right click in the white space surrounding the view-controller (diagram) to get zoom menu options in a pop-up (Note: The Xcode App must have focus for this to work or you will NOT get the zoom pop-up).
In Xcode 7, the shortcuts have changed to the following:
- Zooming out : cmd (⌘) + -
- Zooming In : cmd (⌘) + +
- Normal (100%) : cmd (⌘) + ctrl (^) + =
Right click on the empty area of your storyboard, a popup menu will be shown like below:
You can use this popup to zoom in/out the storyboard (or check the keyboard shortcuts shown in that).
来源:https://stackoverflow.com/questions/24634867/xcode-6-how-to-enable-storyboard-zoom