We are preparing options to force delays on Bitcoins (rule set depending on aggregated 24 hours transfer amount - option configurable from the user) and emergency account lockout (that would automatically cancel any delayed transfer).
Be sure to let it be configurable to at least 72+ hours if the user so desires. In financial markets 3 days as a standard clearing time has a particular history and is a standard for many markets, probably because it's 1 full working day plus the 2 weekend days (as people do not pay close attention over the weekend).