Google's Helen L. posted a Google Places Help thread informing business owners that from now on the reviews on Google Maps, the Google Place pages, will differentiate between those left by Google users and those captured from other places on the web.
Helen from the Google Maps team said:
As of this morning, we've updated the way reviews show up on your Place Page. Now, reviews from other sites will show up under a header called 'Reviews from around the web.' We'll also show a small icon for the third-party site providing the review.
Meanwhile, reviews for your business that were left directly on your Place Page will show up under a header called 'Reviews by Google users.'
Here is a picture:
Google also wrote a blog post on this at the Google LatLong Blog.
Forum discussion at Google Places Help.