watchOS 2 was due for release today. However, Apple has delayed it due to a bug. The company hasn’t said exactly what the issue is.
However, in a statement (http://tinyurl.com/o3frjaf) to the press, Apple says: “We have discovered a bug in development of watchOS 2 that is taking a bit longer to fix than we expected. We will not release watchOS 2 today but will shortly.”