Check out its official US website:
PBS Masterpiece - Downton Abbey
Watch the Season 2 Preview trailer
Also, Season 1 will be repeated (especially for those of you who missed it or still haven't seen DA's first season) in December 2011 in anticipation of Season 2 beginning Jan. 8, 2012. Plus, Season 2 will be shown on PBS Masterpiece Classic in its entirety!