Lots more to this major Google Places update than meets the eye. Not only are 3rd party reviews missing. Citations are gone as well as the more details section.
To see the latest insights from industry pros, head to Mike Blumenthal's blog (below). He currently has 7 blog posts about this update, covering how this affects the review space and discussing whether the deletion of 3rd party reviews from the count impacts rankings.
IMO this was a cosmetic UI "front end" update as opposed to a back end algo update. Even though the info is missing (or de-emphasized) does not mean it counts any less in the algo or rankings. You can read lots of comments at Mike's about this and it appears most agree with my comment above.
Also TechCrunch and the Wall Street Journal have done stories saying they believe many of the changes were initiated due to the antitrust investigations.
I personally think it's more of a competitive move (on several different levels) PLUS I believe G is making more room to integrate Google+ for business.
Citations and reviews count in the algo just as before. This was a front end cosmetic (political) change, not a back end algo change. All experts agree on this.
Google has been hiding most citations for several months and very few new ones showed up in the more about this place section anyway.
So the only change is really that it's more difficult to size up a market, reverse engineer the algo or spy on competitor's citation sources. But there are tools out there that can help you do all the above. You just can't see it with a quick peek at the Place page any more.