The timing of this is very suspicious. The WaPo probably got the story lead straight from Carney or Media Matters. I doubt these lazy journo bums would do any actual work on their own to dig this up.
Could be. Regardless of who actually did the "opposition research," I'd still bet that the method was to compile a list of Romney's high school classmates, get in touch with them, and then pay them for whatever story they could come up with.
The irony and hypocrisy here is that whatever leftist entity did the dirty work likely did it by capitalist techniques (i.e., providing monetary incentives) as they publicly talk about and implement "transformational change" in American society.