I've been spending down time at work going back through old stories of players taking $$ and gifts from agents. There are plenty of cases that we can point back to in history where the NCAA punished the schools involved with sanctions, vacated wins, etc. and it ends there. If the NCAA really wanted to uncover the massive underbelly of the sport, they had justification to do it back with Marcus Camby or even more recently with O.J. Mayo. But they will never be proactive with their investigations, only reactive. It's a "if we don't see it happening, we don't care" game. The FBI comes in with the resources and no stock in the NCAA, ends up following money trails to wherever it goes.
Bottom line, the NCAA will do whatever they can to keep the status quo, too much $$ at stake. Not sure they will come down with the hammer unless there is some push from a stronger entity (i.e. congress)