Hi. I got time to play a bit with UDAs and vibe, and while this isn't much, I think the possibilities for more declarative code looks good. 

module myapp;
mixin CurrentModule;

@(page.get("/")) void index(HTTPServerRequest req, HTTPServerResponse res) {
    res.renderCompat!"index.dt"();
}

shared static this() {
    auto router = new URLRouter();
    router.addRoutesFromMembersOf!__CurrentModule;
}

Notice @(page.get"/") and addRoutesFromMembersOf!__CurrentModule.

Next up is trying to fix UDAs for the inject pattern. Hopefully I can write the following 

@(page.get("/"))
@(requires!(userLoggedIn, hasRights!(addUser)))
void add_user(Params...)( // etc

Is anyone else playing around with UDAs and vibe?