Just a note regarding the bandwidth issue comments: all Apple downloads are distributed using Akamai, a commercial content delivery network (CDN). Akamai has a few thousand nodes as far as I know, spread all over the world, at various datacenters, big educational institutions, etc. Bandwidth is *not* an issue with Akamai.
http://en.wikipedia.org/wiki/Akamai_Technologies and
http://en.wikipedia.org/wiki/Content_Delivery_Network for more information.
edit: If any of you have ever downloaded something from Apple while at school (software updates, Quicktime trailers, etc) and have noticed that it was really ridiculously fast (like much faster than other downloads) then your school likely hosts one or more Akamai nodes.