Why have this many books? If Google can do it, why cant anyone? Besides, at the current exponential rate of Twilight book releases, it will only take a few years to reach that number!
There are debates on Mobileread about why anyone would want to put all their eBooks on an eBook device. I fall in the All Of Them camp. Do people have silly arguments over whether all of your files should reside on a PC or Mac? No. I want to have my entire library with me.