We finally get to hear Groot speak (2:05), in the new Guardians of the Galaxy trailer which was released today after a big buildup (three teasers for the trailer) over the weekend.
 
The characters have been outlined and the tone has been established (see "New 'Guardians of the Galaxy' Clip"), and apparently the classic rock soundtrack theme will be a thing (Norman Greenbaum’s "Spirit in the Sky" will apparently join "Hooked on a Feeling” in Starlord’s "Super Sounds of the 70s" cassette collection).  We finally get to see Glenn Close’s Nova Prime Rael at the one minute mark.  Sadly, no  appearances of Thanos (see "Thanos Role Is Cast").