What does this mean to your business?
Well without user submission of wrong information including address, closed businesses, duplicates and companies not following guidelines it appears that they are going to have a lot on their hands trying to find, fix and suspend listings that don't follow the rules which means most businesses will be competing against companies who don't follow the rules which means you are going to be competing with black hatters until Google gets around to doing anything about it.
Don't get me wrong I am on the fence when it comes to Map Maker for one it's a great concept what better way to update something wrong than allow the end user that is outside a shop that doesn't exist to be able to report or modify the listing with the correct info and on the other hand if Google is the only one to make the edits it will help eliminate wrong info and spammy listings but from what I have seen in the past my fear is Google is going to drop the ball and let black hat listings slide and incorrect info will be all over the search results.
So my best advice to business owners is to make sure your listing is correctly optimized and all your ducks are in a row so you have all the leverage you can for if black hat listings start popping up during/after the transition.
I would love to hear other people's thoughts on Map Maker closing!