First I hate the title Metroid Prime 2: Echoes, it shoudl be Metroid Prime Echoes or Metroid Echoes.
Second.. it looks like ARG -- Alternate Reality Games, have now become the vogue thing to do in terms of grass roots level marketing.
I have no idea how long these websites have been around, but check em out and see if you can put things together, watch the videos, really look at site layouts and the clues are there. I know some folks eat this up...Check out the videos here And Look at this layout, note how it's actually a banner on the channel 51 website..This is an interesting one and quite the shot across the Bow...
Then for more of the last one... www.Iloveskis.com
, and www.iloveknees.com
EDIT: On further inspection it seems like more of a SPOOF on Microsoft's marketing technique, still neat-o none the less...