Yes, that account is "alive and kicking." Frequent Flight Bonus Program miles "never" expire. Of course, after the November switch over, they will be dead. So, make sure you contact AAdvantage to set up the transfer (if you haven't already received a letter notifying you that your account is already set up).
American Airlines AAdvantage Customer Service - (800) 882-8880
Trans World Airlines Aviators Service Center - (800) 325-4815
http://www.aa.com/aviatorsmatch/
http://www.twa.com/ffbenroll/news.html
http://www.flyertalk.com/forum/Forum71/HTML/004562.html
TWA is becoming American Airlines...
Two Great Airlines, One Great Future