So yesterday afternoon, I moseyed on over to the San Francisco Design Center’s Concourse to the launch of the Facebook Platform, a new initiative by the No. 2 social-networking company as it seeks to transform its business to a larger stage by partnering with all sorts of third-party developers.

While there, of course, I ran into a panoply of Web 2.0 denizens and got their take on what queries should be put to Gates and Jobs, seen strung together in the video below.

First up (and best question thus far): Digg founder Kevin Rose, who wanted to know what each of them would do if they switched roles.

Then, Plum founder Hans Peter Brondmo wanted to know why the pair was not jumping onto the open Web and also why Microsoft could not churn out operating systems like Apple.

Entrepreneur Julie Hanna Farris was curious about open-source issues, as well as Web-delivered applications.

Accel Partners venture capitalist Jim Breyer, a big Facebook investor, drilled in on Jobs and asked why Apple had stopped embracing start-ups.

And, finally, Facebook COO Owen Van Natta wanted to know when Microsoft and Apple would starting building on, of course, the new Facebook Platform.