slowmo on 08 May 2013
This is no way confirmed but there is a quite well publicized rumour that the Sega Saturn had a 2nd CPU added late in the design process to try and improve the performance to match the Playstation 1. This might be why there was serious bottlenecks in the design with the shared bus of the CPU and also the various memory access limitations.
http://segaretro.org/Sega_Saturn_Development
http://en.wikipedia.org/wiki/Sega_Saturn
As stated by earlier posters, its highly unlikely to happen but hardware can and has been changed late in the design process before. The example of switching to a Intel CPU by the way would be impossible without a complete redesign, any changes would have to be of very similar architecture.
