Google was also laughed at when they bought youtube but who is laughing now with everyone playing catch up.
you will regret it . your soul is worth more than the whole money in this world . when you say things like this be carefull
They must have big plans for that. A big company like Google would not just spend $100million in something, if they are not sure they can take back that money and profit. I don't think this was decided just in one day from Google's side. I am more then sure that there is a hint, and once Feedburner will be completely under Google's hands there will be some innovation and new features. I am willing to bet $100 on this.
Of course, there is no question they are going to roll out something that will get them one step closer to knowing all internet traffic worldwide. I'd bet my best site on it.