I've learned that the following pilot programs should be available for Winter '10. You should check with your account rep if you are interested in participating in them.

Criteria-based Sharing Rules

Have you ever wanted to share records based on the criteria of a record and not just on the ownership of the record? Have you ever needed to dynamically change sharing based on a change of a record rather than the change of ownership of a record?

Criteria-based sharing rules provide a new way to share records automatically. Rather than traditional owner based rules where the owner of a record defines who to share the record from, Criteria-based sharing rules provide a powerful way of sharing records based on the criteria of the record.

This becomes essential when dynamic sharing is required. For instance, if a Candidate record status changes from an 'Open' to a 'Closed' status, you may not want to share the record to internal users. Or if a PTO request is made by someone from the San Francisco office, only San Francisco Human Resources personnel should have access to the record. Should the location of the PTO request change to the London office, the record will automatically be shared to the London Human Resources personnel and dropped from the San Francisco personnel's list of records.

Edit -- I was asked by Salesforce.com to remove the information regarding the second pilot as it is private.