I have just had a reply from Microsoft that
appropriate teams are working to address this problem, but it is more complex than they initially thought. Take heart, though: MS is aware of the problem and working on it!
Update: This is now fixed. The link to Download a Language Pack for Office 2010 now actually goes to a site to download a language pack for Office 2010. Hooray!
re: download a Language Pack for Office 2010, the link leads to:
404 - File or directory not found.
The resource you are looking for might have been removed, had its name changed, or is temporarily unavailable.
My Spell Check stopped working.
Keyboard Proofing
English (U.S.) <default> enabled not installed
How can it possibly be NOT installed? I've been using it for years.