The CG trailer shows off Silver and Bowser Jr.
While the trailer doesn't show real time gameplay footage, it does confirm some of the new characters and events that will be featured in the highly anticipated title.
From the Sonic side, we have Silver, a time-traveling hedgehog first showcased in 2006's Sonic the Hedgehog, participating at a curling event.
On the Mario side we have Bowser Jr., joining his father at a bobsled race. The already confirmed events, such as ice hockey, snowboard races, and ice skating are also shown.
Mario and Sonic at the Olympic Winter Games will be released fall 2009.