Achieving cohesiveness in such a system will be very difficult though. There's a reason why Apple chose to keep OS X and iOS separate.

I do agree that cohesiveness is important to the user experience. It makes me a little disappointed that the extra step wasn't taken to make the Metro UI live on its own without the full desktop experience tagging along.

I don't think cohesiveness across these systems needs to be a prereq. In classic mode things should work great. In Metro mode things should work great. Bumpiness in transition, IMO, is acceptable for v1.

To put it another way, I'd much rather have bumpiness shipped on day X rather than a delay to clear up all the transition bumpiness and ship 6 months after X. Although I'd like to see updates that fix the transitions come out a 8-12 months after release.

Then why even put Metro on if they are striving for only half a level of perfection? Why not wait until they've got it solid before releasing?

What would make me very pleased is if they delayed 6 months to get it right rather than rush it out.

Why do you keep pushing on the idea that this is some sort of finished release of Windows 8? It's a developer preview, that's alpha stage at best.