New since v2.0 beta 1:

  1. Providers can send unsolicited assertions
  2. Providers can detect and respond to directed identity (identifier_select) requests from relying parties.
  3. Completely stateless relying party support (not even requiring application state — we already had session-less)
  4. More Association members exposed to allow for serialized custom store support (for db-backends)
  5. Better signing security (64-byte key instead of 20-byte key)
  6. Added ImmediateMode property to OpenIdTextBox and OpenIdLogin controls.
  7. New OpenIdMobileTextBox control
  8. Several new samples (2 sites, several more pages) to demonstrate mobile controls, immediate mode, and custom stores.
  9. Exposed application memory stores for RPs and OPs so you can customize more without implementing your own store.
  10. Lots of new tests to verify correct behavior.
  11. Lots of little bug fixes.

There are a couple of minor breaking changes that will result in a compile-time error if you happen to use those features from v2 beta 1 or v1, but correcting the errors are trivial.