Gamble had a few of his big plays, but they were on the defensive side of the ball. Gamble had 3+ game-changing plays during the 2002 regular season.
What he is saying is that you can find kids that are speedy and athletic to come to your school and make plays like Ginn's reverse, punt return or slant. They usually do not have quite as good of balance as Ginn, but there are plenty of lightning fast slashers out there (like Cryami's returner).
It is quite hard to recruit an outstanding shutdown corner. I agree that we might not need Ginn on defense. In terms of recruiting in general, he is much more valuable of an addition at CB than WR/PR/KR. With the depth we have at CB, he may prove to be more valuable to the team at WR. Time will tell.