Yahoo News is reporting Yahoo Search and likely other services are making their way onto ATT's phones. This opens up Yahoo to about 70 million users. However, Google recently made a similar move with Verizon Wireless for their 70 million or so users.
Of course, Yahoo is left off iPhone users as the default search on Safari is Google. Still not a bad save for Yahoo. After all they certain can do with this victory. On a personal note, I've been with Yahoo since my days at UCLA when my roommate, Dave, showed me all the Robotech gears and news I could find on Yahoo's very simple listing at the time.
My, how they've grown. Still, Google truly rocks. And I doubt Android users will be using Yahoo's services all that much if it's tired into Google and, potentially, mobile Chrome in the future.
Nevertheless, this is the kind of things mobile warriors love. Suffice to say, Yahoo Search is geared towards finding limited but more direct items where as Google is a bit more comprehensive. Yahoo's Search may have more appeal to users.
My suggestion as far as Yahoo is concerned is for them to develop a Google app like the one on the iPhone. This way, even if they're not the default search engine on another service, this offers them a back door to users on other services.