They had a DNS screwup, it just took awhile to flush the internet of bad addresses. One thing to avoid such long outages (up to a week) is for the owners to lower number of seconds the data is valid. Clients can avoid this by using a local DNS client, which can be flushed. You can expect that big ISPs (like comcast) keep old data around, and their DNS servers are slow, very slow. If you think a website is down, it could be your ISP's DNS servers either being too slow or using old data.
