I can't think of another case where a major conference has kept the same name yet changed its membership as radically as the Big East has. Just last season "the Big East" referred to a 15-team league in basketball terms. Now that number is down to 10, forming a rather striking new amalgam comprised of seven holdovers in DePaul, Georgetown, Marquette, Providence, St. John's, Seton Hall and Villanova, and three new arrivals in Butler, Creighton and Xavier. So don't be fooled by the same old name. This is, in fact, a much different conference.
What impact will this shift in membership have on the quality of play in the Big East? At the risk of stating the obvious, it's not a good thing when your conference loses both the reigning national champion (Louisville, now found making a one-season appearance in the American Athletic Conference) and a team coming off a Final Four appearance (Syracuse, which is about to make its ACC debut). Connecticut, Pittsburgh, Notre Dame, Cincinnati, South Florida and Rutgers have also moved on. Add former member West Virginia to this list of the dear departed, and the Big East has suffered what can only be termed a mass exodus over the past two seasons.
In adding perennial hoops heavyweights like Butler, Creighton and Xavier, arguably the three strongest mid-major programs this side of Gonzaga, the Big East made the best of a bad situation. And, with top-25 mainstays like Marquette and Georgetown still in residence, the Big East will continue to be regarded as a "major" conference in basketball. The overall strength of the conference is, unavoidably, about to dip. The halcyon days of 2013, when half the Final Four came from the Big East, will be difficult to repeat.
That being said, the Big East is going to have some very good teams in 2013-14. Here's how I see the top of the conference shaking out in the first season of the league's new smaller configuration.