No, the HD camera is facing straight forward. In fact I changed mine to tilt down slightly because I'm not really interested in 50% horizon in my shots, but I think it will be a bit harder to turn it 90 degrees downwards. The downwards camera that is onboard the Drone is close to useless for photography, I believe it makes 320x240 shots or something like that. It's used by the Drone itself for some functions, but it gives really bad quality image. If you want to buy a Drone purely for photography I would suggest to mount another camera under it anyhow, the so called "HD" camera it ships with is not really that much HD at all. It's decent for "nice" shots, but don't expect real professional stuff from it. Furthermore it has a fixed focus which is also not set that well for long distance shot. Again, I had to mod mine to get clear pictures. Modding in this case simply means removing the glue, focussing it to the desired point and fix the lens in place again.
I have no experience in mounting other camera's to the Drone, but as far as I have read on various sites the only really decent camera the Drone seems to be able to lift is a Go Pro. Haven't seen any other camera's mounted to it yet. I was thinking about sticking my old iPhone 4 to the bottom, but haven't done so yet. Still waiting for my 60beat controller to arrive so I can maybe for once fly the drone without crashing it into a wall or tree. When I have my 60beat, I'll try to stick an iPhone to the bottom.