That list is ok, but it would be better if the link in
THIS page (Per sapere dove ? disponibile il Roaming GPRS) worked...
Anyway, Ricaricabile is Prepaid, and Abbonamento is Postpaid, but that's important only for outgoing calls (callback), while GPRS should work with prepaid in the same countries where postpaid works even if they write "GPRS abbonamento". I think Wind's webmaster is not that good!
So you have GPRS also in Canada (I think our Canadian friends can confirm), Australia and Argentina (Personal).
Dati/Fax is the CSD/GSM connection, which is available in more places, but it's not included in the Mega NoLimit option.