I've been telling people that 100Mbit connection (not just from the server, but available from your bandwidth provider) is the minimum for new mirrors. There are a few long-established mirrors with slightly lower capabilities, but we've also added many with 1Gbit/sec or faster connections. You also need about 1TB of disk space to carry a full mirror.
Alas.. I have to drop the idea. I don't have that much of bandwidth right now. In future if I can get a pipe that large, I shall try again.
Thanks. Susmit.