This is actually something I've known for a while now, but wanted to share... and this looks to be the most applicable topic.

The most recent Kreo Build set (Autobot Command Base) was shown at the US & AUS Toyfairs last year, but it ended up being completely different to the version that ended up being released. (with some different Kreons too)
So today I found a site that actually has the prototype shown WITH the released version. (the prototype is the top image)

I wonder why the set was so significantly changed, in such a short period of time (to have a fully built example as the official product image just a few months before its release).