Well, Then Don't
Then don't buy from the Mac App Store.
pro: one less disc to keep track of. my family already lost my iWork disc.
cons: what if i want to format the hard drive and restart from scratch? or even just archive and install? what if i completely replace my hard drive? what if i want to sell my mac and get a new one, would i retain the license or would the buyer get it? how would they reinstall the OS after I wipe the hard drive? how long is this going to take to download? will we be able and authorized to burn our own install DVDs from the downloaded software?
Then don't buy from the Mac App Store.