One thing that's definitely going to be difficult and take up time is dealing with all the legal bullshit and working out what taxes you have to pay etc. if you decide to sell your coins, especially since they seem to be an international company I wonder who's jurisdiction they fall under?
As far as I know they're a U.S. based company, so they'd be subject to the jurisdiction of the U.S. government and whatever state they're incorporated in.
A company the size of Overstock (and especially considering their business model) has day to day expenses in fiat currencies. I imagine they'd probably use something like BitPay, or perhaps a similar system built in-house, to immediately covert any Bitcoin payments to USD in their bank account. In that case, I'd think (layman's opinion, I'm not a lawyer or a tax accountant) that their tax liability would be the same as if they had accepted the same USD payment in cash or by check or credit card.
For the most part this is great news, I've bought things from Overstock before and being able to pay with Bitcoin means I'll be more likely to buy things there in the future. It should also be the final nail in the coffin of the old myth that Bitcoin is only useful for drug deals, money laundering and other such shady and/or illegal things. The only thing that really worries me is his comment about money being too important to be left in the hands of government officials. While that's true (and I'll add that it's too important to be left in the hands of bankers, also), hearing that isn't going to make too many people in Congress happy, they've been allowed for too long to believe that the powers granted to them by their elected office are greater than the rights of the people and their responsibilities to the people.