It could go either way. Problems with something different is that it is also a bigger chance for a flop. As long as that something different doesn't cost much, it doesn't matter much assuming the core features are there. So Nintenmdo has a good chance, but worse case they will be a minor flop but still have a profit.
The PS3 has the best potential to last longer (last to come to next generation). That can be risky as it gives others a head start. Look what the year advantage the 360 gave this gen.
Microsoft always does poorly on their 1.x launches. However, they are good at learning from their mistakes.
The biggest factor will likely be which one gets the best third party support. There is always the chance price or some new feature will make the difference, but generally it's whichever will gain the most 3rd party support... Now systems have such overkill, and more cross platform engines, it's possible they will all have good support.