There is now new information at both aa.com and twa.com on the merger of the frequent flier programs. But yes, you should move all of your MR points into TWA within the next two months, and then come the end of November they will move these automatically into American. The only thing that they haven't said (which may not affect you) is whether these points will count towards their million miler program. If you are sure that you are canceling your MR account, then I would do this sooner than later. FF