For my country the imports from china have pased the imports from the us this year for the first time and chinas importance as a market is growing as well.

There is also th us struggeling with its finances wheras china is swimming in money, and in case anyone hasn't notices they are also on a spending spree buying up knowledge and technologies.
So economicly china could pass the us in the next few years (esspecially if the us keeps on destroing itself).

I Like It That Way. The Bigger Question Is Why Do You Even Care ?

Because it makes you look silly.

In which imagination is the USA still a leader?Every 1st world country is far ahead of you when it comes to the human rights.A lot of other countries have better standards in living situations and what makes living for the people nice.
Without the fear of you using nukes on everyone you wouldn't even be anymore relevant.
There won't be anyone surpass the military power of the USA but this isn't a true leader in these times.Its just fear from everyone outside to not mock you.

You are clearly underestimating the rate of change in the 21st century. Back in the 19th century, when America first surpassed Europe in the first economic super-cycle, her economy was growing 1% over Europe's on per capita terms. China is growing at eight times that rate because it's so much easier to catch up than going from an even baseline to developed status like in the late 1800's. Look up the convergence theory and diminishing returns. 

By 2030, accounting for dollar inflation, their GDP in nominal terms should be a order of magnitude above current values, while the US is growing two and a half times. China's income per capita is going to grow a mind boggling 43 times compared to 1980, compared to 2.5 times in the west. Never before there was a dominance shift this order of magnitude in the planet, not even in the first industrial revolution.

2014
The Mongols will return.

Be afraid.... be very afraid.....

Unless something drastic happens, I don't see huge power shifts and "empires" falling or rising. What I do see is a shift towards a more cohesive and "together" world as the concepts of nationality are slowly fading.

On a serious note, It's only a matter of time before America loses its superpower status.

As the middle east becomes more democratic and stable (And hopefully secular), American influence will decline there. Chinese influence in Africa, is likely to grow, hopefully to the benefit of the nations there. Brazil is going to be the dominant superpower in South America, Mexico is likely to become more influential as well if they can get their shit together.

In due time, they will be a great power, along with EU, Russia, Brazil, India, and China. No idea about the timescale though.

within 10 years China will have surpassed the US however i cant see them being the world power due to their many differences to the western society, especially politically.

!!!NEVER!!!