I thought it looked great, I've loved all of Kevin Smith's movies (well, I just liked "Jersey Girl") and this one doesn't look to dissapoint.
Think it would have been a mistake to put dialogue in this teaser (which is internet only) there's still another 8 months till the movie comes out, you don't want to show people loaRAB of jokes and stuff from the movie too long before it comes out, risks being boring by then. At least this trailer gives you a taste, while leaving most of the plot a mystery.
I like how Jay & Silent Bob just follow Randall and Dante to Mooby's proving (as well as the fact that they had to be in the movie) that hanging around in front of the QuickStop wasn't as much about it being where they'd always hung out, as it was about just annoying Randall and Dante.
Hopefully with the interest this should raise in the franschise there'll be some progression on the Clerks animated movie.