Do you have to have Internet on your Xbox 360 to activate the Kinect?
The Kinect games all have the required updates on the discs. It will prompt you to download the update (from the disc) when you try to play the game. I believe future titles will require you to download updates from their discs as well.
There are plenty of people who play kinect without an internet connection, so I wouldn't worry about it. Assuming you have the newest version of Xbox (unofficially called the "slim"), you can turn on wifi and try to connect to a neighbors connection just for updates, but of course this is frowned upon. :)