I had the same thing happen when I tried to login to the DVC site. My DH found a backdoor entrance! I guess the main entrance was clogged up with people trying to get through! It also varies throughout the day...mornings and evenings are especially busy!
then click on the Disney Vacation Club hyperlink on that page! You should be able to see the DVC site, click on the Members Only link and then login....
The link from the main "disney.com" website hasn't worked for me since last week. There must be an issue with that site. However, as tjkraz mentioned, use www.dvcmember.com That one I used last week when I couldn't get through the other way and it is just fine.