If you were able to log in to del.icio.us but only saw a blank page, this bug should now be fixed (it was due to the PHP type checker freaking out at untitled bookmarks)
Some people will still see a blank screen; that's due to a different bug (a missing shard ID in the user record) that makes delicious confused about where to look for bookmarks. This will be fixed in the fullness of time
Delicious should now be back up in read-only mode, for those who can remember their password. You can export your bookmarks or link them with a Pinboard account. -> del.icio.us