SoundExchange, which collects online radio royalties, and DiMA (Digital Media Association), representing some of the larger webcasters, reached an agreement during a meeting in New York earlier today. The deal formalizes their previous near-agreement to limit $500 per-station minimum royalty fees to a total of $50,000 per year.
This agreement resolves earlier squabbling about minimum per-station fees, but leaves unresolved the stickier question of whether SoundExchange will hold medium and large webcasters to the fees handed down by the Copyright Royalty Board (small webcasters have been offered a deal, although some of them are boycotting it, calling the deal an attempt to "divide and conquer" webcasters, and claiming that it unfairly limits their growth).
Here's DiMA's announcement of the deal: