Besides, warp drive does not exists, why build this particular shape?
StansDDS
True in one sense, but I think in another sense, not..
First, to answer, why make it that shape... Because, its Star Trek!

My goodness man... Thats what its all about. Its Enterprise. Why make a replica of the Titanic and then decide to make it totally different looking. Then it wouldnt be a replica of the Titanic. (Just my humble thoughts).
Back to warp drive. I think we have technologies that could make that thing go. We found evidence of a human camp / base on Mars. I am sure we have places farther out. The Blackbird was flying in 1957 and even today looks years ahead of its time. Imagine what we have now.
Quote from a website;
Allegedly, in the fall of 1943 a U.S. Navy destroyer was made invisible and teleported from Philadelphia, Pennsylvania, to Norfolk, Virginia, in an incident known as the Philadelphia Experiment. Records in the Operational Archives Branch of the Naval Historical Center have been repeatedly searched, but no documents have been located which confirm the event, or any interest by the Navy in attempting such an achievement.
In the late 1930's, at the world fair, the Germans showed a 'disappearing' scale model village that showed a new technology for stealth. (Yes, before WWII). Before an audience, a model of a town on a stage, surrounded by electrical antennaes, started humming. As it charged up, which took about 10 min's, a shimmering became visible when looking at the stage town mockup. At 10 min's into the process, the model had disappeared and you could see clearly through the area, the back drop behind the model village. I think that it was then that we had found out how to shift things out of this physical dimension with 'electrical fields'. I think this is how the Philidelphia was able to disappear, and move at great speed.
Note, on the Philidelphia experiment, they made it to Australia, to a port, rematerialized, phoned in to the naval base here in America, and on the return, a major malfuction occurred where the ship partially materialized as well as people, and some fused into the deck, etc. (Very grim... ) Also, a side effect occurred in the crew where they would often become slightly transparent. Albert Einstein was part of the project and voted to never attempt it again because it was, he said, to extreme of a technology for mankind to be fulling with (at the time).
To bump that up. If you watch and note alot of the present UFO reports and videos, several lights appear, then a craft materializes inside that area. From the giant flying wing over Phoenix (I think 9 lights?) to saucers in China, acorn shaped scouts in Germany's forests, etc, etc... They seem to be able to instantly warp in and out of this 'area' (our place) via these light things. Two videos of a saucer that was hovering next to a building in China formed about 6 or 8 lights (looked like nav lights, large, not connected to the hull) and in 2 video frames (very fast), the saucer became a blurr, in one direction, inside the circle of lights.
So it seems that the shifting or warping or what ever one might call that form of transportation has been around for ages, and man had it back in the 1930's (Germany).
It would be danged cool if we already had 'large' ships that could warp to Mars, or even the moons of Jupiter.... And I feel that we 'do' already have such technology, but I do not think they are as large as Enterprise...