The article was published in hindustan times regarding Prelims in 2011:

The first big reform in the way India selects its civil servants is around the corner.
The government has decided to replace the Civil Services (Preliminary) Examination with the Civil Service Aptitude Test (CSAT), which will test candidates on their aptitude and analytical abilities rather than their ability to memorise.
The UPSC is further expected to push for changes in the Civil Service (Mains) Examination.“The CSAT is expected to come into effect from 2011,” Minister of State in the Ministry of Personnel, Prithviraj Chavan, told Lok Sabha on Wednesday.
A government source said Prime Minister Manmohan Singh had last month approved the revamp of the preliminary exam on lines suggested by the Union Public Service Commission. The UPSC is further expected to push for changes in the Civil Service (Mains) Examination.

But this will be only after examining the response to changes in the first stage.
Nearly 1.7 lakh candidates take the objective-type exam in May every year.
The prelims consist of two papers: the first is on general studies and common to all; candidates can then choose the second paper from a list of two dozen-odd subjects. The general studies paper might be tweaked but it is the second paper that will undergo a major change.
The UPSC had told the government two years ago there was a need to test not just the knowledge of aspirants in particular subjects but their aptitude for "a demanding life in the civil services". It had also recommended bringing down the number of attempts a candidate could take. But Singh has kept this aspect on hold.
A top government official said UPSC chairman Professor D.P. Agrawal has constituted a high-powered committee - under former University Grants Commission vice-chairman Professor S.K. Khanna - to work out the details of the two papers. “The committee has been given time till April-end. Then the UPSC will discuss its recommendations with the government and finalise the content of the paper,” the official said.

We are not sure whether it will come into effect from 2011 or later. They have to confirm it soon or else the effort put by many aspirants will be in vain. It is waste for the aspirants appearing for the first time to prepare in the current format since very few get success in the first attempt. I am in dilemma. Anyway this year my preparation is not that good. So, for me it doesn't matter. But, yeah I bought almost all books including books specific to prelims. We need to keep our fingers crossed for good to happen huh .......