Updated These url’s have been removed and replaced with maps.google.com as the url. I would infer from this that it was in fact spam.
These listings look very similar to those noted by Matt McGee in his article on the restaurant industry in Google Using Surrogate Web Sites? where he noted an upsurge in assigning review site url’s to unclaimed listings in Maps.
Historically Google has assigned its best guess website algorythmically often with upredictable results. These new reports might actually indicate a change in policy or algo rather than affiliate mapspam.
It is possible that rather than Google making a best guess of the url for an unclaimed listing, they are now, either for their benefit or the benefit of trusted sites, sending the traffic to those sites instead. It might just be the assessment that the earlier method was more prone to error than sending the visitor to a know quanity like Yelp or UpperEast.com.