An article based on a PBS Frontline broadcast two days ago, with lots of details:http://www.pbs.org/wgbh/pages/frontl...umbai-attacks/

It will be a long time before the accused appears in an Indian criminal court and the allegations are tested Indian style.

Interesting commentary on Saudi Arabia first:
For the last two years, Ansari lived in Saudi Arabia, where he had been “talent spotting” for another “massive attack,” an official with New Delhi’s antiterrorist police unit told Reuters, though he did not specify whether India was the target.
and second:
Saudi assistance in turning over Ansari would be unusual because Saudi Arabia and India are not natural partners, according to ex-CIA analyst Bruce Riedel. “I’m puzzled by why the Saudis would do this, but it would make sense if they were being pushed by the U.S. and other countries who want Lashkar put out of business,” he told FRONTLINE.