There's tons of video footage, screens, magazine coverage worldwide, interviews, twitter posts, hands on impressions, a massive E3 Dovahkiin billboard...
In saying that, I think we're long overdue for a trailer. I find it ridiculous we're a little more than 2 1/2 months from launch and have only 1 trailer from 6 months ago.
I think that trailer set too high of a bar.
They will never be able to top it with a second trailer.
for example, after watching the Dead Island trailer, everything else I've seen about that game has been a let down. As for Skyrim, even watching gameplay footage alone is exciting, and I can't say that about Dead Island; however, I think it would be really difficult to make a second trailer as good as the January trailer.