My son took the Oct 05 PSAT, May 06 SAT I, June 06 SAT II and Oct 06 SAT II. In each case, the proctor announced when each section had 10 minutes remaining and 5 minutes remaining.
Then he took the Dec 06 SAT I and there were no announcements made until "put down your pencils." It really hurt him because he didn't finish his essay, got flustered, and his "bad karma" showed up in his scores, which were far worse than May in each of the 3 sections (2270 total in May, 1950 in Dec).
Just a warning to future test takers to manage your own time!