Taiwanese movie site udnstars has a higher-quality version of the teaser we saw of Harry Potter and the Prisoner of Azkaban on BBC's Film 2004 with Jonathan Ross in February.
With the greater detail, we can see more of Draco being pulled through the snow, we can hear Harry clearly say "he was close enough to touch" and we can make out Hermione in the background of the very last scene:
Direct download link (right-click to save)
Windows Media format, ~8.7MB
Thanks to Yoshie for the tip!