[doug*platypus]

So, summing up so far the possible kingdoms are:

Erebor
Dale?
†Arnor(†Arthedain, †Cardolan, †Rhudaur)
Angmar
Gondor
Rohan
Mirkwood/The Woodland Realm


I have marked with a † the kingdoms which no longer existed at the time of Saruman's conversation, but haven't included Angmar since Witchy clung pitifully to the fact that he used to be a king.

Is there any proof that Umbar was a kingdom? The references to The Corsairs of Umbar seem to me to point to a loose arrangment such as that of Esgaroth. Dol Amroth was a part of the kingdom of Gondor.

If Dale was a lordship and not a kingdom (similar to what Lórien became), and if the three perished kingdoms of Arnor were counted separately, this would make seven. This of course doesn't prove that these are the famed Seven Kingdoms with Seven Crowns, but it does point to it being a possibility.