More than a month ago I have seen a post by Joerg Jaspert on the Debian devel announce list that was announcing the inclusion of the amd64 port in the official Debian mirrors. At that time only the unstable branch was included, and he explained that amd64.debian.net will maintain the testing tree until this will be fully synced with the debian-installer so the Debian Etch system will use only Debian mirrors. If you are using the stable release (sarge) then this would not affect you in any way, as they will continue to keep it updated.
Since I manage several servers with Debian Etch AMD64, I was very happy to see that the amd64 port was finally approved and included in the official mirrors. There was no date when this will actually happen for the testing release, but it happened exactly as described: after a period of no updates, today you will notice 404s from amd64.debian.net, and this means it is finally over…
Ign http://amd64.debian.net etch Release.gpg Ign http://amd64.debian.net etch Release Ign http://amd64.debian.net etch/main Packages Ign http://amd64.debian.net etch/contrib Packages Ign http://amd64.debian.net etch/non-free Packages Err http://amd64.debian.net etch/main Packages 404 Not Found Err http://amd64.debian.net etch/contrib Packages 404 Not Found Err http://amd64.debian.net etch/non-free Packages 404 Not Found
So in case you are using the AMD64 port on Debian testing, you should go ahead an change your sources to no longer use amd64.debian.net, and choose your prefered Debian mirror: http://www.debian.org/mirrors/list For example if you had:
/etc/apt/sources.list deb http://amd64.debian.net/debian-amd64/ etch main contrib non-free
change it to something like (please use your prefered mirror, as this is only an example using the main US mirror):
/etc/apt/sources.list deb http://ftp.us.debian.org/debian/ etch main contrib non-free
Once you do this and try to update / upgrade your system, you might notice that there will be quite several packages that will be updated even if they are the same version (just a different build).