The Mummy: Tomb of the Dragon Emperor director Rob Cohen has announced on his Blog
I just wanted to let you know that, as I promised long ago, the TEASER TRAILER will appear here on my blog before anywhere else, Friday May 16th at 9:00am PST. I'm really stoked, and I think the trailer guys at Universal (led by Frank Chiocchi) did a great job. It will make its US debut in theaters May 16th with prints of Prince Caspian, and will make its international debut on prints of Indiana Jones on May 22th. I'm really looking forward to your reaction. So crank up the sound and view it full screen as soon as you can!
He talks more about the visual effects and scoring here. for the movie that you'll be seeing the teaser trailer this Friday online and in theaters.