I'm stoked to see this game is making it to Live.
http://features.teamxbox.com/xbox/1840/CES-2007-Xbox-Live-Arcade-Roundup/p1/

Granted the write up on the game doesn't say much if you haven't played it before, but it is one of the best board games ever I think.

If you have never heard of Settlers then check this link out:
http://en.wikipedia.org/wiki/Settlers_of_Catan

It will atleast give you an idea of what to expect. It is an easy game to pick up I think, but the trading and strategy involved can be very deep.