Federer loss significant, but what are long-term effects?

After the shocking semifinal just 24 hours prior, where Jo-Wilfried Tsonga stunned the No. 2 player in the world, Rafael Nadal, it seemed nothing could have upstaged that spectacle -- or could it?

Novak Djokovic outplayed, outhustled and outmaneuvered Roger Federer in every facet, ending a remarkable run by the world's top player Down Under. Djokovic's growth and maturity from last September's U.S. Open final was palpable. He counterpunched intelligently and was aggressive from the onset.

He also attacked Federer's second serve consistently, applying relentless pressure on the two-time defending champion, not allowing him easy games. The Serb took advantage of the slightly slower Plexicushion Courts -- just introduced this season -- which subsequently neutralized Federer's always-aggressive game. A frustrated Federer was flustered when his game did not have the same effect on Djokovic as it does with other players.

The slow surface hindered his attacking style and that manifested itself throughout the encounter.

This was one of the few times the Swiss looked like the slower player on the court. And that, in large part, is due to Djokovic's phenomenal court coverage.

Federer tried to get himself motivated in this match. His second-set letdown really hurt after forfeiting a break, and eventually the set, in the first. By the time the third rolled around, though looking rejuvenated, it was too late for the two-time defending champ.

The ramifications of this match are significant: For the first time in five years, there's doubt as to who the year-end No. 1 player is going to be. Federer will unquestionably win more Grand Slam titles and likely break Pete Sampras' all-time record of 14 majors, but it's going to be an arduous process.

Federer, though, now has time to sit back, take it in and adjust. He's rarely in this position. In 2005, he lost to Marat Safin in the exact same situation: the Australian Open semifinals. The Swiss won two Slams that year. He'll enter Wimbledon as the predominant favorite and the U.S. Open will suit his game far better than the Aussie did.

It's going to be an exciting year. Players realize that beating Federer at prestigious events is no longer a myth. Nadal is likely to dominate on clay again and will be a heavy favorite at the French. Djokovic has shown he's adept on any surface -- proven by four consecutive Slam semifinals. The emergence of Tsonga is intriguing along with other players: Andy Roddick, Nikolay Davydenko, David Ferrer, et al who occupy the top 10.

The idea that Federer will dominate as he has the last four years is far-fetched. He's still the dominant player on tour, but his competitors now have confidence he is beatable and capable of off days.

So then, who is the most likely player to pose as Federer's most significant threat to his stranglehold atop the rankings? That's the $54,000 question.

Because there are more hard-court tournaments, the slight edge has to go to the Serb. But the clay season is not far behind and Nadal can make up ground -- especially if Federer goes out early in any of these events. The Spaniard is a viable player on hard courts, too, and had a shot at the Australian Open until running into the buzz saw, Tsonga.

For now, though, Federer is No. 1 and there's no reason to think that's going to change in the immediate future. There are myriad reasons to explain why he didn't play up to his standard level of excellence versus Djokovic -- the courts, the fact that he came in to the tournament just getting over a virus -- but it was the manner in which the Serb handled the pressure and then handled his opponent that produced this stunning upset.

Patrick McEnroe, the U.S. Davis Cup captain, provides analysis for ESPN.com during the tennis season.