I think this is the same sort of thing as the Newcastle research reported a few months ago on similar lines. It isn't proven as a 'cure' and can only be undertaken under very close medical supervision as so few calories for so long is potentially going to leave you without a lot of the things your body actually needs. As far as I know, there is no long term follow up and only a small number of subjects have taken part. Also, a lot may depend on the reasons for the diabetes - no doubt you would lose weight which would reduce insulin resistance, but if you had no weight to lose then it's unlikely to help.
I think it's interesting, but misreported in a lot of places as though anyone can just reduce their diet and they would be cured, which is highly unlikely even if the diet could be safely followed by anyone. Moreover, you would only be cured if after the diet your levels remained normal after a carb-heavy meal or a snack of fast carbs, which I haven't seen any detail to confirm is the case with the research participants.