The Serpant comparrison is inevitable i guess, due to the launch's being fairly close. However, as Spenner says it is actually funny - because so far as far as we can all see, their drivers are essentially running Durango chassis rather than S500. Clearly no-one knows why this is, but my guess is that S500 is further away from being ready that some people would like/hope.
As and when you time your releasing of info, it is very very difficult to get it right - and the bottom line is you will never please everyone. If you anounce it too early, you lose interest. If you leave it too late people make other plans. If you release pictures too early, there is a chance someone could copy your ideas before you actually get things to launch - depending on how far away you are. What do you do for the best? no idea, which is why i'm in engineering rather than marketing