Well what do you think? I guess there will always be people interested in the people that came before them, so chances are, people will still enjoy looking for their ancestors!
But have you ever though what records will our decendants will be trawling through by then? Will there still be 10yrly census returns, or will they more likely be hunting through mobile phone records, credit card statements, & mortgage agreements? or even the odd forum or two...
Any more to add to the list?