Gamespot has a story on ST's announcement that as of March 26, 2004 they will be shutting down their older v1.0 servers.

This comes after users having over a year now to trade in their copies of v1.0 for the newer v1.1. You can still trade in your copy of v1.0 so that you will not be shutout when the v1.0 servers are no more.

Sonic Team will honor this shutdown by running the v1.0 servers for free for a week before they shut them down.