iPadOS 2 was originally released on September 25, 2011, as the second major version of iPadOS (formerly known as iOS for iPad). However, if the question is about the most recent or upcoming version, the latest major release is iPadOS 26, announced on June 9, 2025, at WWDC and released on September 15, 2025. Apple has switched to a year-based numbering system starting with this version. If more details about the original iPadOS 2 release or the current iPadOS 26 release are needed, please specify.