I see nothing wrong with praying for Ted Kennedy's health, but I think the prayers should be directed more to his recovery from the way of thinking that Ted has, especially when considering his position as one of the lesser leaders of our country.

My prayers would be more directed towards asking God to use this "stroke", if it is that, to destroy that part of Ted's brain, which causes him to be such an enemy of himself and this country.
There might not be much to work with after considering Ted's lifestyle, but it would be better for him to enter heaven with a quarter or less of his brain, than into hell with what he has left now. Jesus said something like that.

It would be quite a miracle that would bring glory to God, if Ted would recover as a new person in Christ. I would truly enjoy seeing how God's enemies would react to such a recovery.