Steven Sinofsky wrote some excellent advice for product managers in his post Shipping is a Feature: Some Guiding Principles for People Who Build Things. I especially like this part:

A decision means to not do something, and to achieve clarity in your design. The classic way this used to come up (and still does) is the inevitable “make it an option”. You can’t decide should a new mouse wheel scroll or zoom? Should there be conversation view or inbox view? Should you AutoCorrect or not? Go ahead and add it to Preferences or Options.

But really the only correct path is to decide to have the feature or not. Putting in an option to enable it means it doesn’t exist. Putting in an option to disable means you are forever supporting two (then four, then eight) ways of doing something. Over time (or right away) your product has a muddled point of view, and then worse, people come to expect that everything new can also be turned off, changed, or otherwise ignored. While you can always make mistakes and/or change something later, you have to live with combinatorics or a combinatoric mindset forever.

The flip side of this is, of course, that the organization needs to agree that product managers have the autonomy to make these kinds of decisions.