[iconfinder]

"It's an adage in UX that when you see an interface that asks the user to customize the layout, it means the designers gave up trying to find the right solution themselves."

It's always depends on the app. If you have a tool where you primarily have heavy users e.g. a programmer's IDE - then customization makes sense. But in the case of Google+ I don't see the point either - it just adds extra complexity.

[logic]

Think a/b testing: if your users start customizing around a particular pattern (particularly in larger numbers), there might be something to learn from that.