I just found this information in a thread on the Ameniti cancellation (http://tinyurl.com/2a38vm
- thanks SanDiego1K ^ ) and IMHO it deserves its own thread:

An Important Message

For years, Silver Wings Plus has brought members numerous opportunities to earn extra miles and save on travel.

As part of United Airlines' efforts to control costs, optimize revenue and respond to customer feedback, we have decided to discontinue the Silver Wings Plus program. Starting July 1, 2007, Silver Wings Plus will no longer offer annual memberships. And, effective immediately, Silver Wings Plus will no longer activate, renew or extend annual memberships.*

http://tinyurl.com/2gxd76

I notice the fine print at the bottom may apply to those of us who are "Lifetime Members."

* If you joined Silver Wings before September 2005, you will retain access to special Zone Fares. Just call United Airlines at 1-800-720-1765 and refer to your Silver Wings member ID for more details.

Maybe I should have clarified before signing up whether the "lifetime" referred to mine or to the program's.