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That was the blog title from a recent post on the APM website which was written in response to the current work being undertaken to refresh APM's Body of Knowledge (BoK) (from version 6 to 7). The post - you can read it here - talks about how PMOs are not really mentioned in the BoK at all, instead they'll get a mention in the area that covers off the different types of roles that exist in project management.(take a look at the proposed contents)
And that - from the Chartered Body for the Project Profession - dear PMO colleagues is your lot.