This is a fairly massive issue for those of us with pre-existing content in other wikis or CMS, or who wish to convert others from wiki X to DekiWiki. I would also argue that Deki's adoption rate and success will be determined in no small part by the ease with which wiki content can be imported (to allow wiki fans to easily migrate to DekiWiki).
I have a fairly large TWiki wiki, and at present, I'm reduced to cutting and pasting HTML from TWiki to DekiWiki. New lines get added, links have to be manually removed and recreated one-by-one, and files have to be uploaded. Needless to say, I've had more fun watching paint dry...and then crack and flake off with age. Of course, the revision history is lost, but that's a complicated issue that I don't expect DekiWiki to be able to do much about (TWiki uses RCS for revision tracking). But there must--or should--be an easier way.
I know you all offer services to help migrate from MediaWiki to DekiWiki. If you were willing to expose that functionality, that alone would be a major help (I believe there are ways to translate TWiki to MediaWiki markup). Ultimately, though, any means of importing multiple HTML pages is desperately needed, it seems to me.
Anything that smooths and accelerates the migration path helps MindTouch dig not only into wiki-less organizations, but also allows wiki-using organizations to start reaping the benefits of DekiWiki with minor hassle, making DekiWiki a much easier sell.