I see these changes sticking, because Google is trialling paid ads in Google Maps/Local/Places/Whatever-it's-called-this-week.
I read on Mashable about a week back that Google has already tried a pilot of the paid local placements in San Francsico.
As a few other users have said, this gives them a way to monetise organic SERPS.
In the UK I'm yet to see the hybrid results that Tedster spoke of (i.e. organic results with markers next to those that have 'place' pages). All I'm seeing is 'maps' results displayed normal size. Sometimes the top two results will be traditional organic results.
For most of the niches I watch (local tradesmen and service providers) the 'local' results are choked with spam. A few companies with multiple sites and mobile numbers are flooding the index. One term I saw had eight local listings from the same company. Whatever the algo is for these results, it is an order of magnitude less sophisticated than the traditional organic SERPs.