Without much hoopla Microsoft rolled out a newly revamped section of Xbox.com for viewing XBLM content.  The new section of Xbox.com now allows you to view gamer pictures and themes as well as list of demos, music videos, trailers and arcade titles.  The biggest change is now you can search for movies and tv shows online to see what's available.  This is a great way to keep up to date on what's now available in the marketplace.

I personally find navigating the XBLM menus on the console a little less than helpful so by offering the ability to browse content online is a great feature.  I just recently saw Michael Clayton was available in HD online so I'll be downloading that once I add a few points to my account.  If you haven't been keeping up with what's available online hit the link and see what's out there.

PS If you still are unsure how to download a movie onto your 360, there are little videos that walk you through the entire process.

Source:
Xbox 360 Fanboy - xbox-com-adds-u-s-xbvm-media-details