Nintendo Switch will release on March 3, 2017 worldwide. In the USA it will cost $299.99.
They talked about a little about a few other items around the console. It will have online gaming and will be compatible with your smartphone. Immediately after launch, players will be under a free trial period. It will expire in the fall and then there will be a cost to continue using online services. Finally, they specially announced that there will be no region locking.