If you were among those affected by disappearing Choice points (I told you to move them to Southwest asap for a reason!) you can rest assurred they have not disappeared into thin air.
According to Amtrak they will simply be reverted back into Amtrak points.
From that point you can redeem them for any Amtrak rewards, or transfer them to a program like Continental’s OnePass.
Additionally you will be able to transfer Amtrak points into Choice points at a 1:3 ration between 12/14/07 and 12/31/07.
Beware: Starting on 01/01/08 you will need to be elite on Amtrak or have the no annual fee Chase Amtrak World Mastercard in order to make any point transfers from the Amtrak program!