According to reports from several people who have seen the teaser, it ends with the line "Fall 2013," offering the first concrete hint of when the redesigned Mac Pro might launch. At WWDC, Apple gave a "later this year" release date.
The new Mac Pro was originally teased at WWDC 2013 in June when Apple said it would be coming later this year. Taken literally, Apple's declaration of "Fall 2013" focuses the Mac Pro's release date to potentially any time from September 22nd through December 20th. Apple debuted two new Macs in October of 2012: the new iMac and the 13-inch MacBook Pro with Retina display. If past is prologue, Apple may repeat the cycle this year with the Mac Pro, but time will tell.
Let us know if you've seen the teaser in the theater, and what movie you were going to see.