@Eilon , @davidfowl , @yishaigalatzer , @rynowak 
Well, was thinking about the problem at hand, ```IInlineConstraintResolver``` is needed by the ```TemplateRoute``` (or more specifically by the ```TemplateParser```), now the problem is ```TemplateRoute``` gets created at startup by ```RouteCollectionExtension``` methods (```MapRoute``` to be more specific) and the only way to pass an argument to ```TemplateRoute``` would be either to
a. pass all the way as an explicit parameter to the extension methods, 
Or
b. To make it a property hanging off ```RouteCollection```
Option a is  bad for the obvious reasons, while for option b. we can actually have a property which exposes service provider, which can then be used appropriately.