You are correct. Yahoo is migrating delicious user to use their Yahoo login instead. It's currently an opt in process. If you migrate to a Yahoo login there are some additional integration between Delicious & Yahoo. (but 3rd party software must update their login process)
I made a fake Yahoo account & could not get Quicksilver to scan delicious. This is a good time to mention I'm running QS β54 (3815) in OSX 10.5.8. Maybe QS β58 in OSX 10.6 does not have this problem? Either way I'm not migrating my Delicious account yet. The reason I was considering it is because Facebook got rid of the Delicious integration but now you can sync your public feed with using a Yahoo service (if you're using a Yahoo login).
