The Disciples of Boltax have made available a scan of a draft of Transformers: The Movie script from 4/27/1985. The draft is a result of Transfans pooling their money to try and get hold as many pieces of history from a recent auction from writer Ron Friedman including the draft. The Disciples have a copy of the script available at their site here
It turns out there was some remarkable differences in the early draft and the final movie that include core Transformer concepts that was not originally part of the movie. What is interesting is you can see how the seeds were laid for what would become the final film as some ideas were tweaked, others tossed, and in many cases redone from scratch.
For example there was no "Unicron", instead the main villain was "Ingestor", who merges with a planet and transforms it. The Matrix was also not in the film instead replaced with the concept of "Life Sparks", something that was abandoned until Beast Wars and now a core TF concept. The Life Spark moments in the script were removed or replaced such as Prime's Life Spark moment being repurposed for the transfer of the Matrix in the final film. Also, Devastator had to do battle "Dragon Beast", a new Autobot combiner derived from animals that merges into a dragon. Another change is the draft is when Hot Rod is used as a shield by Megatron against Optimus, he says "Prime...forget about me...Terminate him!" along with other lines to clarify that moment. Missing is the classic "One shall stand, one shall fall" line.
Anguirus at the TFW2005 boards posted a summary many differences between the draft and the final film here. The script is interesting read and worth the time for any fan of the Generation cartoons and movie.