I have a feeling people are confused about bankruptcy...
Bankruptcy is when you cannot pay your creditors. When you can't pay all the people you owe money to, you need to have a third party, you enter into a legal state called bankruptcy. Bankruptcy can mean several different things. Creditors may take partial control over your company, or you may have to sell off everything you own and pay what you can. Marvel was in bankruptcy for years before emerging as a healthy company. THQ on the other hand had to sell everything to pay what they owed.
So, for Nintendo to go bankrupt they would have to first burn through all of their cash assets. Even if we assume losses jump to about half a billion a year, they still have 24 years to go before they run out of cash. But, Nintendo also has long term assets. For example, Nintendo is the majority owner of the Seattle Mariners, a team whose value is estimated at 650 million or so. In a dire emergency, Nintendo could sell them and have somewhere around half a billion in cash to fund their key operations. If Nintendo was to liquidate a good deal of such assets, we're probably looking at something like 28 years before they run out of money.
Running out of money is NOT the same thing as bankruptcy. Nintendo would have to owe someone money before they could go bankrupt. So, even after running out of money, Nintendo would need to borrow a sizable sum of money, have that money come due, and be unable to pay it. So, we're probably looking at at least 20 years at the current rate before they go bankrupt.
That's not to say Nintendo can't go out of business. If they think they just can't succeed they might shut their doors, or sell the company or whatever. They're not just going to operate at a loss for 20 years, even though they probably could.
Right now, Nintendo is listed as having 0 dollars in debt, and over 12 billion dollars in cash. Sony is listed as having 8 billion or so in cash and 16 billion in debt. To say that Nintendo is more likely to go bankrupt than Sony is absolutely insane. If Sony makes a $100 million dollars a year for the next 5 years, they have a good shot at bankruptcy. If Nintendo loses a billion dollars for the next 5 years, they wouldn't go bankrupt.
http://finance.yahoo.com/q/ks?s=NTDOY+Key+Statistics
http://finance.yahoo.com/q/ks?s=SNE+Key+Statistics