Only just noticed this (which probably says a lot for how I've been using the site for a while!). So, the end was in sight for Delicious... now a move has happened instead as it headed to AVOS and the ownership of the founder of YouTube.
To be honest, I'd been using Diigo for ages - not least because of the additional annotation tools and groups but also because it allowed me to maintain the presence I'd had on Delicious for a few years by auto-forwarding my bookmarks.
It'll be interesting to see if this fairly recent acquisition sends me back to Delicious 'properly' or if it'll remain a little lost and unloved.