First, we've added an export feature that lets you download a file containing your entire bookmark set. The file stores data in a standard HTML format and can be used to import your bookmarks into most browsers (Firefox, IE, and Safari are supported). If you use another website that needs your bookmark data, chances are that you can feed it this file.
Secondly, we've made it possible for you to import bookmarks from Delicious. Simply tell us the username to import from, and we will fetch the 100 most recent public bookmarks found in that Delicious account, and add them to a newly created folder in your bookmark set. You can use this feature to import your own Delicious bookmarks, or to import interesting public bookmarks that another Delicious user has made available.
The 100 bookmark ceiling is a limitation of the Delicious API that we are using (one that does not require us to ask you for your Delicious password).