Must be a nightmare if you have $100k+ in bitcoins and it is all dependant on you keeping one 256bit private key secure.
What is more you have no real "Police" or "Courts" to help protect you (as they do not understand bitcoins).
Also you have the dilemma of sell or not!
Luckily I only have 1.62 bitcoins that I bought just to try the whole thing out - so I really do not care if someone finds out my private key!
I think I'd be perfectly happy knowing I had a $100k wallet.dat and would not be losing any sleep over it at all
Personally, I'd split the coins out over a few dozen wallet.dat files and keep them all on different USB drives in various places to reduce the risk of failure, loss or theft!
If I had $500k in bitcoins (at today's exchange rate), I'd sell maybe half and keep the rest, and buy gold bullion & real estate with the $250k. Diversification is key!