OpenID 2.0 to OpenID Connect Migration (aka OID2 to OIDC Migration) is a spec that allows RPs to associate the old OpenID 2.0 identifiers to the new OpenID Connect identifiers without user intervention or extra round trip.
The spec has been under development for approximately half a year and has recently gone into WGLC.
During the WGLC, several comments were gathered and the WG decided to normatively change / simplify the verification rule.
In the draft 01, the OpenID 2.0 identifier was returning public key of the issuer but it is now returning the issuer in draft 02. This actually simplifies the verification rule as well as it would make it more flexible.
The diffs can be found from here:
and the HTML version of the document can be found here:
 Working Group Last Call