Tim Lambert who blogs at Deltoid has good information about the 'DDT' controversy:

http://scienceblogs.com/deltoid/ddt

Check out this blog post, which is quite enlightening concerning the present situation.

Two quotes:

"The fact is that until 1994, DDT was the WHO's insecticide of choice for malaria vector control."

"Nor did WHO stop promoting DDT....Alan Schapira rebutted such claims in November 2004: WHO has never given up in its efforts to ensure access to DDT where it is needed....And the WHO's 2004 statement on ITNs (nets) vs IRS (spraying) clearly supports IRS in regions of unstable transmission...."

It's a good post, read it.

Also check this one out, about the new policy.

As for environmental stuff, this is from the Telegraph article you linked to:

"So far, the clearest adverse impact of the pesticide has been a steep decline in the number of bird species in areas where it has been used." Birds are vital to the natural world. They spread plants by eating the seeds and control pests. It's no accident that Rachel Carson's book Silent Spring concentrated on birds - when they go, the natural world will go badly out of whack.