I was wondering if any of the ewallet providers have some form of dead man's switch. Let's say Bob has 200 BTC in an ewallet, and another 5000 offline somewhere. Could Bob set up a system so that, if he dropped dead, his wife or kids would get an email with detailed and fool-proof instructions as to how to retrieve both amounts?
The better question is, why do you not trust your wife enough to tell her NOW: honey, on this here piece of paper there is stored 5,000 bitcoins.