The recent Second Life database breach makes me wonder if websites will want to continue capturing as much info as they can on registration and usage. The practice has been to capture info that is not immediatley useful to the website. Register for Yahoo! Mail or Hotmail etc. and you will be asked many questions that have nothing to do with sending and receiving email. The belief was that all this user info could be of future value.
Now though it may be advantageous to capture less info. Capture just the info you need to use the service and nothing more. That way a breach does less damage.