Hm, week-old post, but I'll answer anyway.
I tried, and they told me no. Seemed at the time to be a TWA policy. I don't know if it has changed since (this was over a year ago). Despite Priceline and Hotwire stated policies, standby varies by airline. Continental rerouted a friend of mine on an entire two-flight segments with confirmed seats on the new flights. United has a stated policy allowing standby. On most others it's up to the agent. TWA did give me FF miles on my Priceline flights, but they didn't allow a standby.