According to him, it's nearly four minutes long and "racing"!
He reports, "Elijah Wood has aged, which is impossible to believe but true, he looks like he's disintegrating before your eyes."
And the teaser apparently shows Gandalf the Grey's incredible transformation into Gandalf the White.
Reinhart also reports glimpses of Arwen, the Uruks and Eowyn as well as Pippin up a tree!
The trailer's expected to be tagged onto the end of The Fellowship Of The Ring in the next few months.
The film itself is due out in the UK at the end of the year.