Feature request: postpone updates

Hi,

I would like to suggest a feature for your fabulous plugin: Let the user set a value on how long to postpone available updates.

The scenario for me is that I maintain several wordpress sites. If some day one plugin or even wordpress itself would deliver a bad update, it could break all my sites in a short period of time. So I would like to set the update on an unimportant site to “immediatly”, while letting important customer sites wait some days before updating.