Is the Big 4's dominance in men's tennis has run its course?

The complete dominion Roger Federer, Novak Djokovic, Rafael Nadal, and Andy Murray (aka "the Big Four") have had on the tennis world over the last decade has been a spectacle.  These four men have separated themselves infinitely far apart from everyone else and have done so with truly appalling reliability.
Since the year 2005, only three other men outside of the Big Four have had the honor of having their names engraved on the winner’s trophy at one of the four majors (Marat Safin—2005 Australian Open, Juan Martin del Potro—2009 U.S. Open and Stanislas Wawrinka -2014 Australian Open).
The big four – Roger Federer , Rafael Nadal , Novak Djokovic and Andy Murray have combined to keep out the other players as they went about collecting 37 of the past 41 Grand Slam titles in an march that was barely challenged. But there have recently been signs of brittleness and this is enough for the lesser known mortals to capitalize.
After threatening to grab the title from Djokovic in both Melbourne and US Open last year, Wawrinka made good on his promise at the Australian Open this January. Wawrinka is now ranked ahead of Federer, took his confidence into the finals, where he defeated Nadal in a gem of a match. With Wawrinka’s win the players have had renewed confidence to win and make it large at the Grand Slams and the Masters Series.
It appears that Wawrinka’s example has helped fuel the dreams of the back-bench boys that have kept him bleak company for the past many years. But a look at the winners is like a light at the end of the tunnel.
In the current stage men’s tennis is in, all roads to greatness run through the Big Four.  Ascendancy and splendor in the tennis world is most commonly defined by winning Grand Slams.  But these four champions have added their own definition to achieving such prominence.  Greatness is not only defined by winning a major; it is also defined by beating these four men in the process.  This has proven irrefutable because it is an almost certain reality that winning a Grand Slam requires victory over at least one of the top four players.
So this begs the glaringly obvious question: Can a Grand Slam be won by a player outside the Big Four in the near future? Can this impenetrable castle of unfettered dominance be toppled even if it only marks a temporary transfer of such desired power?
As history tells us, the answer is yes.  One must look no further than the 2014 Australian Open for the isolated narration of the brief dissemblance of supremacy.  Stanislas Wawrinka did the seemingly impossible and conquered the game’s two greatest champions as he defeated Rafael Nadal and Novak Djokivic.
Lleyton Hewitt, Gael Monfils, Richard Gasquest are some players who look dangerous and have been showing ominous signs with their increasing impact in the tennis arena. Before this year the inexplicable Gael Monfils last won a title in 2011 at the If Stockholm Open. But after an impressive performance against Nadal in the finals of the Qatar Exxon Mobil Open in January, Monfils weaved his way past Richard Gasquet to win the Open Sud de France in Montpellier.
Another player to look out for is Juan Martin del Potro. He is someone who has already won a major in 2004, appeared in domineering form as he coasted to victory at the Apia International in Sydney. Just when observers believed that he had enough armory for another assault on the invincible four, his wrist began to bother him again. Tomas Berdych last won a title way back in Stockholm in 2012. Finally, though, the man many believe to possess Grand Slam pedigree bathed in joy at winning the title in Rotterdam. Coming at a tournament where both Del Potro and Murray fell in the quarters, it underlined the Czech’s quest to remain in the hunt.
Players like Marin Cilic and Kei Nishikori have made successful attempts in retaining their trophies and have been learning in the top arena day in and day out.
Tennis could use some variety, and the bunch at the back could do the game a mighty favor if they can overcome their fear and release their best at the mighty stalwarts that rule the game.