Runs very smooth on my GTX 285 for 700 lights.

I can see that only few lights affects each 3D objects.
And it's simple 3D cubes !
So putting 700 really doesn't mean nothing
Instead you should do a demo displaying how many simultaneous lights are affecting the objects each time and put it on a complex 3D scene instead with houses , trees, terrain to see how it behaves!

Only last 3D cards with pixel shaders 4 if i'm not wrong ???
Allow to do deferred shading : lot of simultaneous dynamic lights affecting the entire scene. Before it was impossible or performance was incredibly bad with standard shaders.