There are dozens of reports from business owners complaining their reviews listing on their Google Place pages are missing, or many are. There are many threads with complaints, but I'll link you to one at Google Places Help.
In that thread, Googler Stephan S. said:
Thanks for bringing this issue to our attention and sorry for the slow response.
We suffered a temporary indexing outage beginning of October that prevented us from correctly serving reviews for some listings. The reviews should now be restored. Very sorry for the trouble this has caused for some of you!
Please let me know if you are experiencing further problems. If you are, please provide me with the following information to help us get to the bottom of the issue: * URL of the affected listing (you can find it by clicking on "Link" in the top right bar of your listing's Place Page) * are reviews missing from the "Reviews by Google users" or "Reviews from around the web" section * date reviews went missing * number of reviews missing
Forum discussion at Google Places Help.