Although the High Court today agreed with the judgment of the lower court about the death sentence given to Kasab, I'm sure we are still some distance from the final denouement. The Supreme Court is still there. Most likely, it will agree with the opinion of the High Court as it does in most cases. And the villainy in this case was probably perpetrated in a rather public manner making it quite easy for the Court and the prosecutors and quite tough for the defense.
Oh, and we should not forget that this is what passes for a fast trial in India. The usual humdrum trial takes far longer than Kasab's trial has taken. After the Supreme Court, there's the appeal to the President of India. The President likes to take a lot of time — historically.
All in all, may be by November 26 next, Kasab will still be around and then there will be some hue and cry about why he is still around. Beyond that, I am not sure.