If history teaches us anything the more powerful hardware never usually wins. Its all about content and more importantly price
MS's path down two console types (if true) is an interesting approach. Essentially at launch you are splitting the user base into two camps who will get two different experiences. Then the dev teams who will have to optimise two different versions of a game. Will the lower spec machine restrict the game types of the more powerful machine.
IMHO this is a very messy route to go down and breaks what fundamentally console gaming is about a common playing field with everyone on the same piece of hardware. Its great that it will allow a cheaper entry point into Xbox but it will fragment the owners and community IMHO.
I know this gen we have had the X and Pro but essentially they are just faster versions of the same machine with 4K enhancements. My guess is that MS will follow the same pattern. However the difference is this time they are supposedly doing it at launch.