...that's locked. (Note the lack of 'downloads' in that URL).
I tried several browsers & got the same result, so it isn't a cookie. You're really able to that URL without a password?
EDIT: This is actually the URL linked-to when you click the 'more widgets' button that appears when you display the list of available widgets. And it's locked!
I see now. http://www.apple.com/macosx/dashboard/
is asking for userid and password. This might have been done for a reason or not. I would try to contact Apple about the problem. It could possibly be a mistake. They have almost redesigned the whole site.
The webmaster at Apple is probably watching the site stats with Tiger being released. And noticed that that restricted page was getting hits, and changed the link. It would make sense that they are watching it because it has almost been redesigned and with Tiger being released they want to make sure everything works.
Note, I did a clean install and registered with Apple. I was able to access this page with my Macs user name and password and get many more widgets. Weird, but since you are installing software, I guess it kind of makes sense, but is this a good practice?