Just found some Halo Wars videos online. I have yet to hear about these, so I am guessing they are new…
http://www.youtube.com/watch?v=Z-hZvQbg1is&mode=related&search=
This has been on up for download on live for at least a week now, so it’s not exactly hot off the presses, but people who don’t check ‘new arrivals’ on marketplace on a regular basis may not have seen it.