Yes, I think WinRT will be extended to desktop applications. I believe Microsoft focused on Metro apps first for the Win8 release because it was the most urgent one (tablets) while desktop apps already have an existing ecosystem. Now the focus is on bringing WinRT to the desktop so that these new apps can be integrated with the App store and communicate with other WinRT/Metro apps.
I agree. It took a huge effort, and all available resources, just to get Win8 and related products out the door. They obviously chose to defer desktop updates to get the new products out the door, as would anybody. I expect it was in the plan all along that the next wave would move some attention back to the desktop. WinRT (or some variant of it) will be extended to bring the same programming models and APIs to the desktop. XAML (and HTML) clearly will play the same role there. .NET is no different than it was other than targeting WinRT now. It only matters to the compiler. Write in a .NET language or a native language as you wish, it doesn't matter. I think (hope) that the next releases will show a lot of unification and cleaning up of the rough spots.
The big problem has been a string of developer-relations disasters. So, they wanted to keep the details of Win8 a secret -- fine. But a series of poorly worded statements, followed by deafening silence did a lot of damage with developers. Products that people were deeply invested in have been orphaned without any real direction of where things are headed. Old technologies still work, but for how long? Microsoft used to be so good about developer/product roadmaps -- one of the best companies I have ever seen for laying out the plan for where things were going and when they would arrive. We need that back. A lot of confidence has been lost. We all know how much harder it is to bring customers back after you have lost them. MS needs to let the world in on the secret sooner than later, before programmers slip any further away.