Common misconception, but Bitcoin transactions are instant.
It's only the confirmations that take some time. Confirmations is what makes a transaction 100% irreversible. But nowadays, for regular payments of 'normal' amounts (up to a few thousand $) it's completely safe to accept a payment as soon as it appears in the network (and has enough tx fee).
With todays network strength it's pretty much impossible (not to mention way, WAY too expensive) to successfully forge a valid looking transaction (thus it gets propagated through the network) that doesn't get confirmed. Only in order to accept or trust payments for BIG amounts, e.g. when literally sending tons of money around, you better await a few confirmations.
So, in most situations it's perfectly valid to say that Bitcoin payments are already instant. NOT 10-60 minutes!
Agreed, for the price it would cost to do a successful 51% attack you could buy an army big enough to invade countries like Qatar.