This patch adds the option to link-manager.php to edit checked links en masse and assign to a new category. This is an ongoing complaint about WP 2.1 merging links and categories into one management tool. Also assists folks who may have made the move and lost link list association to a default link category such as Blogroll - specifically people with loads of blogroll links who don't want to or have time to manually edit the category of each link.
The patch also includes some javascript to ensure that when one of two options - Delete checked links or Edit changed links is called, the AYS still is active on delete submit.
I think this needs to go into 2.2. The earlier the better as folks are still in the "migrate from 2.0" stage.