I'm working on integration with deckbox.org, the current 3.2 was supposed to be able to import CSV files in their format but there seems to be some issues with that, not sure why yet.
There's also a feature which should hijack the export of your deckbox stuff if you do it in iMtG, and import it as a Magic Binder. If you're deckbox user, give it a try please http://deckbox.org (Inventory/Tradelist/Wishlist -> View -> Export).