The video is unusual, in that it shows (camouflaged) Explorer prototypes being driven off-road, before the product has been revealed. This isn't often done in the industry.
The video also shows the Explorer playing in the sand and mud, doing some more-than-casual offroading.
Even though the 2011 Explorer is going to be a unibody design with front-wheel-drive powertrain, it looks like Ford has some more serious off-road capability built in.