A glance at the top 25 polls right now might cause some college basketball fans to do a double take. Contenders typically seen in the rankings: UConn, Illinois and Maryland have been replaced by perennial conference doormats Virginia Tech, Washington State and Vanderbilt. Even several mid-majors have worked their way into the polls. Some of the biggest programs in college hoops, however, continue to struggle to reach the “also receiving votes” category.While a handful of big-time teams have become mired in mediocrity, and some mediocre teams have risen to power, it’s easy to wonder what happened and how things changed so quickly. Only a season ago, UConn was an upset loss to George Mason away from the Final Four. And just two years ago, Illinois went on its undefeated streak. But as has become the norm these days, graduation, and more significantly players leaving early, has decimated some of the big programs, leaving them noticeably absent from their normal spots on the national stage.North Carolina’s return to contention immediately following a national championship, despite losing its entire starting lineup, has become the exception to the rule. Losing as many players as the Tar Heels did is tough for any program to overcome, as we’re seeing this season across the country. Don’t forget, though, that like this season’s struggling powerhouses, the Heels went through hard times recently as well. Only five seasons ago, North Carolina was bounced in the quarterfinals of the NIT, and the season before that, in Matt Doherty’s final season as head coach, the team finished with an 8-20 record and missed the postseason entirely.Other teams atop the polls right now, especially last season’s finalists UCLA and Florida, had similar experiences. Only through rebuilding and finding the right pieces — be it recruits for the Gators or a new coach for the Bruins — did those teams finally return to the top after suffering through uncharacteristically bad years.Currently, Kentucky, one of the most dominant programs of the past decade, is fighting its way back to the status it once enjoyed. Ranked No. 25 in the coach’s poll, the Wildcats have begun their resurgence. But stuck in a dog-eat-dog SEC conference they still have not completed the restoration to glory.As the “big boys” lose players, second-tier conference teams — usually relying on experience and cohesiveness — have been able to step up and make statements within their respective leagues. Looking across the power conferences this season, the leaders are not teams that have been traditionally successful. Parity is spreading throughout the NCAA.Ohio State and Wisconsin have jumped Illinois, Indiana, and Michigan State for Big Ten supremacy, while second-year member Marquette sits right behind Pittsburgh in the Big East. Virginia Tech is amazingly atop the standings in the ACC, and after Kansas in the Big 12 comes Texas A&M — a school never known for its basketball prowess.As the disparity in talent levels between conference teams dwindle, inter-conference games have become unpredictable this season.In the SEC, seven of the 12 teams have appeared in the polls this season. But because the talent levels between teams are so similar, few of those schools can consistently remain there.In fact, no SEC West team has a winning conference record right now despite having three teams with legitimate tournament hopes.On the West Coast, no conference has been more difficult to predict this season than the Pac-10, where six of 10 teams have been ranked at one point or another. In a league typically dominated by two teams — some combination of Stanford, UCLA and Arizona — there are five teams with a shot at the conference title this season.Parity isn’t just victimizing the power conferences. Although three mid-major teams (Nevada, Air Force and Butler) are highly ranked right now, no team has been able to distinguish itself among its peers the way Gonzaga and others have in years past.Sure Gonzaga and Southern Illinois — traditionally the top two mid-major programs — are having success this season, but they’re being overshadowed by newcomers to the bracket-busting scene as well. Practically the entire Missouri Valley Conference, as well as other surprise teams, is establishing itself as dangerous.Considering the difficulty to stay dominant year-in and year-out, even in the mid-major conferences, the success teams like Kansas and Duke have had in the modern era look even more impressive.Duke, which plays in college basketball’s most famously difficult conference, the ACC, has only missed one NCAA tournament since 1984, despite having oodles of players skip onto the NBA ahead of schedule. Kansas, also a top program for the past decade, weathered the loss of longtime head coach Roy Williams, in addition to the NBA defections, to remain the Big 12’s elite team.So what does the future hold in store for UConn and Maryland and Illinois? Well, if past experience is any indication, the wait shouldn’t be too long before these teams make it back to the top again.Kentucky has already started to re-emerge after a break and Notre Dame has too. And certainly Florida, UCLA, and UNC showed what they’re capable of after suffering through down years.Looking at history, traditionally strong programs like this year’s group of fallen giants don’t stay down for long. As time goes on, the success they once basked in will eventually return. Until then, though, teams like Virginia Tech and Butler will be able to enjoy their moments in the sun.