Final Four Appearances by Conference:
last 5 years: ACC (6) and BE (2)
last 10 years: ACC (10) and BE (4)
last 15 years: ACC (16) and BE (4)
In other words, over the last 15 years, the Big East has a grand total of 4 Final 4 appearances by only 2 different school (UConn and Syracuse). The ACC has had 16 final 4 appearances in the same period by 4 different schools (Duke, UNC, Maryland and Georgia Tech). In terms of national championships, the ACC has 5 over the past 15 years (Duke 3, UNC 2 and Maryland 1) and the Big East has 3 (UConn 2 and Syracuse 1).
It is quite clear from the numbers that the ACC has dominated the Big East (and the rest of the country for that matter) over the past 5, 10 or 15 years (you choose your time interval). The only period that the Big East really dominated was that short period when Ewing was at Georgetown. However, even in that period, the ACC won the national championship in 1982 and 1983 (the Big East cleaned up in 1984 and 1985 with 4 appearances and 2 titles).
Unfortunately, I think that the Big East is much better than the ACC this year...