Evidence of coordination between Obama and "independent" group?

David Brock's plans put on hold by the Obama campaign:

With barely a whimper a few weeks after its big launch, David Brock’s much-hyped Progressive Media USA has collapsed, thrown under the bus by Team Obama. (See previous blog entry here.) Two weeks ago [sorry–I’ve gotten behind in my blogging] the ambitious 501(c)(4) group, which vowed to spend $400 million trashing John McCain, quietly announced it would “dramatically scale back its efforts in deference to the wishes of the [Democratic] party’s presumptive nominee,” the Washington Post’s Chris Cillizza reports.

So much for Brock’s claim that the George Soros-sponsored group would be independent and nonpartisan.