Mel Kiper Jr. isn't as sold on this NFL draft class as a whole as some others around the league are. Kiper, who has been evaluating draft prospects for 35 years, thinks there are some holes.However, some good news for the San Francisco 49ers, Kiper does believe with the masses in this regard -- he thinks the receiver and cornerback positions are stacked and those positions just happen to be the two biggest need areas for the 49ers.In a near-hour conference call with NFL Nation reporters, Kiper repeatedly talked about the virtues of the two positions.