thanks for keeping us updated and fixing bugs, guys!
you're the best -- part of the 'Machines' hive is restored now (thanks once again!), but everything nested below: http://options.wordpress.com/category/machines/computers/networks/internet/world-wide-web/web-20/weblog/weblog-hosting/ is not.
it's actually a whole tree as well. for example there's still missing a link to the "Global Tags" category in the sidebar.
I also use this link in my posts (to find all relevant posts on my blog), but it returns:
HTTP/1.1 404 Not Found
not sure if this related to the "CURRENT ISSUE: Categories and Links" (just don't remember in this very moment how it was before the CURRENT ISSUE), so just in case (hope it won't hurt too much):
category links on the backend Manage/Posts page in the 'Categories' column now are pointing into Global Tags pages, instead of showing all of the posts posted into particular category on my blog -- which'd be consistent (from the point of UI usability) with an 'Action' done by a 'View' link for an individual post in the adjacent untitled column in the same row (same post ID).
category 'Filter' drop-down on the backend works just fine though!
Your links should redirect correctly now.