Producing net-energy is a different story than collecting net-energy. NIF just blows up a canister with a pellet and takes forever to reload a shot. On the other hand, an at-least-as-promising technology like Dense Plasma Focus (http://en.wikipedia.org/wiki/Dense_plasma_focus) is still receiving minuscule funding. I'm hoping to be able to meaningfully support DPF and other fusion technologies soon. DPF has my attention so far because of its scaling characteristics.
What does producing energy mean if not collecting it? The conservation of Energy tells us that we are not actually producing any energy, rather we are converting energy from the mass of the reactants (hopefully into electricity). If you consider the energy converted from mass to be produced, then it is impossible to do nuclear fusion without producing net-energy (as long as you stay on this side of lead).
Yes but in the real world there are inefficiencies. We can't even transfer energy efficiently enough into the reaction yet to get a net energy gain from the fusion reaction. And once you reach that milestone, you still have to make transfer of the yield energy into useful work efficient enough to make the whole thing productive. Efficient energy transfer is hard!