Looked around: - no way to upload existing browser bookmarks (in fact, no way to bulk upload bookmarks at all) - no browser extension

I have about ~1k bookmarks, synced with XMarks and backed up regularly, and currently Delicious is clearly not a compelling alternative.

Unlike some other commenters, I like the new design.

EDIT: Apparently it's doable on the old version: http://export.delicious.com/settings/bookmarks/import