Well, i think a key difference is that the Works Progress Administration directly employed people (as far as my understanding goes).

http://en.wikipedia.org/wiki/Works_Progress_Administration

The difference in what Cuban is suggesting is that he's just asking why the government can't loan directly to businesses to hire.

Right, but that's why I'd say it is a modern take on it. It actually makes the program more like an opportunistic specialized VC/investment bank combo.

From your link, emphasis added: Created by order of President Franklin Delano Roosevelt, the WPA was funded by Congress with passage of the Emergency Relief Appropriation Act of 1935 on April 8, 1935.

funding seems like a sort of crucial detail to me.