The only way to improve your reactions is to put yourself in the environment whereby your reaction time, hand eye co-ordination and footwork are being tested. In the beginning of the video you will see Shoaib Akhtar bolwing to Matthew Hayden and Ricky Ponting. Would love to know their heart rates during these few overs that Shoaib let some rockets fly.
Anyway if you wan't to improve your reaction to be able to handle super quick bowling you have to just test yourself and get in there. Find a quick bowler and get him to bowl from a meter closer or get someone who can really zing the side arm and use a new ball. This won't be the most fun you will ever have but it will make you a better player.