From the release notes of beta 1:
Extended range ISO values (Lo and Hi) for Nikon cameras such as the D3S are now recognized to derive high (and low) {iso} values such as 102,400
Excellent! I can confirm this indeed works much much better than before and I now do get correct ISO information shot with lo/hi settings on e.g. my D3.
I still don't get the correct value for the hi setting (ISO6400) on my D200 though, so the new algorithm isn't complete yet... Hope it can get extended to cover these instances too.