I'm pretty sure you can only waitlist for Saver First class seats if you are able to confirm either (1) coach saver award space on the same flight or (2) first class award space on another flight. Keep in mind that if you are confirmed in first class on another flight, and waitlisted for your preferred flight, if the preferred flight opens up less than 21 days prior to departure, you will have to pay a $75 change fee for switching to the preferred flight (Platinum elites exempt).

http://www.continental.com/web/en-US...ticketing.aspx