In the next version of workflow we are going to leave the XOML extension behind us. Creating workflow’s or custom activities using markup will create a XAML file instead of the now familiar XOML file. That doesn’t mean we are moving to exactly the same same format as WPF as WF is quite different in its nature.
But at the same time we seem to getting a new file extension named XAMLX. So what is this XAMLX all about? Well it turns out this is a markup file containing both the WCF service declaration as well as the WF service implementation. Is this a good thing? Well I am really not sure yet. XAML markup works great for hierarchical items like WPF forms or nested WF activities but a service interface is a different thing.
Guess I will have to think about this one some more.
Enjoy the CTP!