Finally, the guys at Valve are implementing a new WON ID system that will create a single ID for each CD key, as opposed to the current 3 keys per ID system. Hl.net stated that, "if internal testing goes smoothly, all HL clients will be issued a new WON ID on Thursday." Here's the whole write up, straight from the HLDS mailing lists:
This is indeed a blessing for HL server admins. Much thanks to Erik Johnson at Valve for implementing this.When fully deployed, the updated system will use a single WON ID for all users (for those unaware, the current system provides up to 3 IDs, 1 per AuthServer, for a user). Remember that WON IDs are based on CDKey and users with multiple CDKeys will have 1 ID per CDKey. The updated system will stop the Unban hack as soon as it is fully deployed.
For those of you maintaining lists of banned IDs on your servers, be aware that during the rollout period, IDs will be unstable. No user will have a guaranteed WON ID until the rollout period is complete.