I would have written up a reply sooner, but E3 kept me quite busy.
I have mixed feelings about the trailer, too.
The animation is spot on. It looks as good, if not better than Sam & Max: Freelance Police (the game that LucasArts foolishly cancelled). The new Desoto looks especially nice. However, the voices are a different matter. I don't particularly like Sam's new voice. I cannot put my finger on it, but it doesn't sound right. Max's new voice sounds okay. In general, though, the voice acting sounds a bit forced. Although, I'm sure that the voice actors will improve in time for the first episode. Still, it's a shame that Bill Farmer and Nick Jameson were not available, or were demanding too much cash (whichever the case may be).
Regardless, I still cannot wait to play the game. It's near the top of my "must have" list, and this year's E3 has put a lot on that list.