Apple mentioned Force Touch during the unveiling demo, and there is a blurb in their documentation as well:

"Force Touch. A small screen can only accommodate so many controls. That’s why Apple Watch introduces an entirely new interaction model: Force Touch. As well as sensing touch, the Retina display also senses force. Force Touch interactions display the context menu (if any) associated with the current screen. Apps use this menu to display actions relevant to the current content." [1]

I've heard people compare this to a long press, but its subtlety different. Force touch can bring up a context menu faster, because you don't have to wait to determine if a touch is "long" or not

[1]- https://developer.apple.com/library/prerelease/ios/documenta...