For the developers they get more accountability and are able to talk with their users if they want more information. It also might slightly discourage some fake-negative reviews (e.g. anti-competitive reviews).
For users it has all kinds of negative consequences. You will need a G+ account to review at all. You will appear in Google search results (i.e. potential employers can find that you downloaded the Angry Birds app). It will allow developers to both harass reviewers directly (via G+ messages) and indirectly (use G+ information to find them in the telephone book and call them/send them a rude letter/sue them).
All in all it is a mixed bag. I think in general the response to this will be mostly negative. Blizzard tried this with their Battle.net accounts and it resulted in a massive amount of bullying, harassment, and in general problems. They were forced to pull it soon after.