Games like this happen at every generation turnover and generally result in the best playing, most polished, and content-rich games ever. It is a wonderful thing to work with hardware you are familiar with at a comfortable level so you can really focus on gameplay and design rather than struggling to balance technical achievement vs stability.
That balance isn't just for the engine programmers, you know. It is a constant back-and-forth examination of every pass and piece of content in the game, often cockblocking artistry and gameplay concept until the right compromises are figured out. And if you do take it on, in the end you'll only get something moderately nicer rather than all the technological advancements (in graphics and physics and such) of something designed exclusively for next gen from the ground up.
