My ppt wasnt too bad, took me a lot less than essays. I think I did it in probably 3 or 4 days. I had something that was really easy to decide to do it on. I went for a much more illustrated presentation. A lot of people are going to just make lists and bullets of stuff in an attempt to make it almost another essay. I wanted something more interesting than that. The adcoms read enough essays that I think they will appreciate something more visual.
Also I made sure NOT to use the 200 words. They pretty much said that they wanted the ppt to stand on its own so I made an effort to have it make as much sense as possible without resorting to explaining everything.
I think after this is all over it would be fun to post all the ppt presentations and see how everyone attacked that question. Though we may want to take those down before people start applying next year incase GSB asks for a ppt again next year.