Otto,
I'm not sure the next step is going to metro style dialogs. I think metro is a try of creating an unified interface for mobile and touch devices in windows platform, but I don't know if the market will follow Microsoft in this change. I think there is a lot of people using computers with XP, Vista and Seven and they don't will change their computer soon. So, we will have to develop for Windows desktop for some years more.
I don't think that change the interface to metro - or else - is only change the aspect of the controls. You have to embrace the new interface. You can't change an interface of a Windows program to Mac only changing the controls to another with Aqua style. In different platforms the controls do different things. I wrote about this in this post
http://cincomundos.wordpress.com/2008/0 ... lataforma/Before changing the interface of my programs, I will think whether it makes sense doing so. If my programs will continue running in a desktop computer, I think that the effort of the change does not worth. If the market goes to PC with touch screens in the next years, I will reconsider the change, but if only is an aesthetic change without an increase of functionallity of the application I'm not sure I will do it.
Kind regards,
José Luis