In addition to what Dimension10 said, we have (are) also imported (are importing) questions listed here and here in the blog, and some get rather spontaneously imported at present.
The final procedure in the long run will be to list questions that should be imported on the Request for import votes thread, accessible from the top menu bar.
Aside: inappropriate questions (imported or not) can be listed in the corresponding community moderation threads (they mimic the review queues of SE) accessible from the link Moderate in the top menu bar.