I am not a lawyer and following is not legal advice of any sort. However:
It appears that some DV winners think that proof of funds is not required at the time of the interview. Per DV guidelines, proof of funds at a minimum poverty line IS required. At interview, one may or may not be asked to provide bank statements showing sufficient funds that are equal to or higher than minimum poverty guideline. (
see this link)
What if you don't have sufficient funds?
If one is asked but cannot produce evidence of sufficient funds and if one's DV application is denied then he/she permanently remains on file as having expressed clear intent to immigrate to the US. This may (but doesn't have to) be taken into consideration if one would like to visit US in the future (visitor, travel, study...etc). In essence, one's visitor's (or student's) visa could be denied on grounds on previously unsuccessful DV application, since DV application constitutes immigrant intent and visitor's visa should not be used to enter and stay indefinitely in the US.
Bottom line: I would not go to an interview if I were not absolutely prepared and have all documents required for the interview. The requirements for DV are so simple (but strict) that each person can very easily determine whether or not they will get the visa.
Nevertheless, every person decides on their own whether or not to pursue DV application, at their own risk.