As of January 2009, it is the University of Miami (50).
USC
For the 2009 season, that is the University of Miami with 40 players that have played in at least 1 game during the season. LSU is second with 38 and the University of Texas is third with 37.
Brigham Young University annually has the most white players on both their football and basketball teams. Northwestern University has the second most.
I do not know the totals for 2005 alone, but did read recently that Miami (FL) leads all schools with 42 players currently in the NFL. FSU was second with 41.
UCLA has 14 active players http://www.uclabruins.com/sports/m-baskbl/spec-rel/062809aab.html
The University of Kentucky in 2012 placed a total of six players in the NBA, five in the first round and 1 in the second round. This included the first time ever for the first and second draft picks from a single University.
your mothers
For MLB players active on June 8, 2009 that is Ken Griffey Jr. with 617. Alex Rodriguez is second with 561 and Jim Thome is third with 550.
The University of Michigan had 45 active players on NFL rosters in 2004 The University of Miami had the most on opening day rosters for 2004. Here's a web page you can use to download an Excel file of rosters: http://www.i-aa.org/article_print.asp?articleid=60119 Opening day roster belongs to Miami. But Florida and Notre Dame share for most active in 2004 at 40. I believe??
TEnnessee
Canada by a landslide