Vanessa from the Google Maps team posted a thread at the Google Places Help forums informing Google Place business holders they may receive emails from Google notifying them that their listings will be updated.
Vanessa explained these email notifications are to inform you prior to when Google makes the update. Here is what Vanessa said:
Some of you may have received these very e-mails from us yesterday. Let us know if you have questions.
We use both manual and automated ways to ensure that new information being applied to your listing is accurate before it goes live. We are sending the notification e-mails in advance of pushing the edits live to your listings. Clicking edit and submit in your Places account is the best way to let us know if you disagree with the edit. If you sign in and do that at any time - either before the edit is implemented or after the changes are made - your listing will maintain or revert back to the state it's shown as in your Places account.
Here is a picture of an email I received on Friday:
So don't be worried if you received this email, this is legit.
Forum discussion at Google Places Help.