"A Big Ten team that has finished 9-9 hasn't been left out of the [NCAA] tournament."
Not to get picky Fran, but that's not true, though I understand what you're trying to say. Going as far back as the 1992-93 season, 6 teams finished the Big Ten regular season with an exact conference record of 9-9 yet did not play in the NCAA Tournament.
1992-93: Gophers
1994-95: Iowa, Penn State
1995-96: Michigan State
1996-97: Michigan, Michigan State
Note that from 1997-98 through 2006-07 the B1G only played 16 conference games, so there were no 9-9 teams. In that time period (10 seasons), 13 B1G teams finished with a conference record of 8-8 or better yet did not play in the NCAA Tournament (at least a couple were ineligible anyways because of NCAA sanctions):
1997-98: Iowa (9-7), Penn State (8-8)
2001-02: Gophers (9-7)
2002-03: Michigan (10-6), Gophers (8-8)
2003-04: Iowa (9-7), Michigan (8-8), Northwestern (8-8)
2004-05: Indiana (10-6. ... who can forget the memorable "We're the 4 seed" mantra from Mike Davis after IU was eliminated by the #5 seed Gophers in the conference tourney quarterfinals), Ohio State (8-8)
2005-06: Michigan (8-8)
2006-07: Iowa (9-7), Michigan (8-8)
All that said, I agree that the Hawkeyes could be dangerous this season, despite their horrific nonconference schedule. In short order, McCaffery has done a nice job making the Hawkeyes relevant again.