Yahoo! announced late tonight that they have agreed on terms to acquire Right Media (time to update that Wikipedia entry) for $680MM (20% of what Google paid for Doubleclick). This acquisition comes after an initial investment in the privately-held firm back in October, 2006.
Right Media has it's own ad-network (ReMix Media), but it's strength comes from a marketplace publishers can benefit from. By loading multiple publisher offerings in the Right Media system (including Google Adsense and Yahoo! Publisher Network) publishers can have the highest eCPM ad delivered to their waiting web visitor.
I've played with the interface and it's pretty slick. I'm looking forward to meeting the team and seeing how we can all make Yahoo! more competitive in a number of different areas. Welcome to the team! Yahoo!