I found the release trailer to be quite beautiful, but at first glance fairly lacking in information. I watched it a second time via that youtube link, and I noticed a few extra things- that one guy is an ODST, not a spartan; that there's a covenant ship hovering in the clouds near the end; and that Elite is still as beautifully terrifying as the first time.

All in all, the more times I watch it, the more excited I am. Can't wait for the HD versions. HBO reports that it should be online by 3am EST (midnight PST)