DV lottery which is also known as green card lottery allows natives of eligible country people only to apply for the program. DV Lottery is designed for the people who were born in the eligible countries and not by the citizenship of the applicant.
If the person was born in Ghana and now is a citizen of UK is eligible to participate in the DV Lottery.
If a person was born in India and now he holds the citizenship of Bangldesh is not eligible to participate in the DV Lottery.
DOS will announce that which country natives are eligible to participate in the dv lottery and which country natives are not eligible to participate in the coming DV lottery around the month of September.

As per the DV 2011 green card lottery natives of the following countries were not eligible to participate in DV-2011:
Brazil, Canada, China (mainland-born, excluding Hong Kong S.A.R. and Taiwan), Colombia, Dominican Republic, Ecuador, El Salvador, Guatemala, Haiti, India, Jamaica, Mexico, Pakistan, Peru, the Philippines, Poland, South Korea, United Kingdom (except Northern Ireland) and its dependent territories, and Vietnam.

No one country can get more than 7% of the available 50,000 US Immigrant visas in a given year diversity visa lottery program.
DV Lottery winners name list for country wise will not be available.
Following countries got most winners in the DV 2011.

GHANA NUMBER OF WINNERS 6,002
UKRAINE NUMBER OF WINNERS 6,000
NIGERIA NUMBER OF WINNERS 6,000
BANGLADESH NUMBER OF WINNERS 5,999
ETHIOPIA NUMBER OF WINNERS 5,200
KENYA NUMBER OF WINNERS 4,689
EGYPT NUMBER OF WINNERS 4,251
SIERRA LEONE NUMBER OF WINNERS 3,911
CAMEROON NUMBER OF WINNERS 3,674
IRAN NUMBER OF WINNERS 2,819
CONGO NUMBER OF WINNERS 2,575
RUSSIA NUMBER OF WINNERS 2,464
MOROCCO NUMBER OF WINNERS 2,003
GERMANY NUMBER OF WINNERS 1,895
ALBANIA NUMBER OF WINNERS 1,469
ARMENIA NUMBER OF WINNERS 1,268
BELARUS NUMBER OF WINNERS 1,104
AUSTRALIA NUMBER OF WINNERS 683

Read the DV 2011 instructions.
http://www.travel.state.gov/pdf/DV-2011instructions.pdf