Well with the Andaman Islands being a possible hot bed of LTTE maybe it was taken so as to be used against the Govt of Sri Lanka? Filled with god knows what to be flown 911 style into something important in Sri Lanka??
Can we cease all this talk about hijacking the plane to 'use later'?
If you want to hijack a plane and fly it into a building you do just that and have the element of surprise on your side. You don't hijack a plane, fly it a 1000 miles, land it somewhere then attempt to use it again when the eyes of the world (and every satellite & military asset in the region) are looking for that one plane.
Apart from anything else, how many people do you think would have to be involved in an enterprise like that?