Jeremy via the Yahoo Developer Blog clues us in that Yahoo has "lifted many of the restrictions associated with the Yahoo! Maps APIs. Until today, the APIs were available only for non-commercial use unless you applied for an exception. The concept of commercial and non-commercial has gone away and exceptions are no longer necessary in most cases".   [bolding and italics added by bold Italian Renaissance Artists]

Although I'm not surprised about this (Yahoo and Google reps at Mashup Camp in February were indicating that the future for API use was going to move  along these lines) I think it's superb and cool and a huge hat tip to Yahoo for, as usual, getting the big Web 2.0 picture right and right on.
The concept is echoed by Eric Schmidt at Google in his recent LA Times interview:
We don't do our own content. We get you to someone else's content faster. 

As a publisher I'm loving this.  Give me simple but robust tools and an advertising network and I'm happy to find content and work to create sites and share the revenues with those who manage the network and the APIs.