The Key Discovery draft currently includes this definition:

6.2 NamedKey interface
WebIDLinterface NamedKey : Key {
    readonly    attribute DOMString  name;
    readonly    attribute DOMString? id;
};

and says that the id should be the base64 encoded representation of a sequence of no more than 256 bytes.

Whereas, JWK defines the "kid" (Key ID) field as a case-sensitive string in http://tools.ietf.org/html/draft-ietf-jose-json-web-key-27#section-4.5.

These should be aligned.  Specifically, please change the name "id" in this structure to "kid" and state that its value is a case-sensitive string.