Let's not get carried away here.
Hear is Providence's Big East records since 2001
2001 - 6-9
2002 - 8-8
2003 - 11-4
2004 - 4-12
2005 - 5-11
2006 - 8-8
2007 - 6-12
2008 - 10-8
overall - 58-72
Iowa's Big Ten record since 2001
2001 - 5-10
2002 - 7-9
2003 - 9-7
2004 - 7-9
2005 - 11-5
2006 - 9-7
2007 - 6-12
2008 - 5-13
overall - 60-72
Looks to me like they have been on pretty even ground this decade. But, take a look at the all-time basketball rankings compiled by ESPN. Iowa ranks 10th and Providence 78th - really no comparison.
http://assets.espn.go.com/photo/2009/1004/cbe1.pdf
If you take a look at the Sagarin conference rankings by years:
2001 - big ten 4th, big east 6th
2002 - big ten 5th, big east 4th
2003 - big ten 5th, big east 4th
2004 - big ten 5th, big east 2nd
2005 - big ten 3rd, big east 2nd
2006 - big ten 4th, big east 5th
2007 - big ten 6th, big east 3rd
2008 - big ten 1st, big east 6th
So the big ten average conference rank this decade is 3.875 and the big east is 4. Doesn't appear the big east has this big advantage that some think it does.