I got word today from Verizon that SuperPages advertisers (horizontal links across the top) will appear in MSN local search results. This is an extension of Verizon's existing relationship with MSN, which provides the listings for MSN Yellow Pages. Verizon has been working aggressively to expand its network, as have other online Yellow Pages publishers.
Also very recently YellowPages.com announced an expanded distribution relationship with Yahoo! very much like this.