Clearly Google is confirming that local search is very important and signaling to local service providers and brick and mortar stores that they should pay serious attention to their local listings and making sure the local listing is optimized.

What are the implication for paid search or sponsored listings and traditional SEO?

It may be too early to tell but I think that if you want to be found but do not have a physical address in a certain city you will need to use paid search to get seen there. Yes Google Places will allow you to define a radius for a service provider but the competition for space may make that irrelevant.

SEO will continue to be important for broad reach such as regional reach or national reach. Searches done without a geo identifier do not show the Google Places listing but rather still show the traditional ten organic listings and sponsored listings in the way that we have been familiar with them.

We will keep watching this development. But meanwhile look to optimizing your local listings or see your site fall from page one of the search engines