It looks like a rather intimidating task to build an Inline::D module but it would definitely interest me to try it. I've not looked into the guts of the other Inline:: modules but the Inline's documentation says this:

For C (and C++), Inline uses the DynaLoader::bootstrap method to pull your external module into Perl space. Now you can call all of your external functions like Perl subroutines.

Other languages like Python and Java, provide their own loaders.

I must admit I have little clue about loaders like this. I gather from this that I would need a loader for D, which I have no idea whether exists or how to fetch one. :-)