No, for two reasons:
First, Bitcoins are very divisible. So it wouldn't create the kinds of problems having a penny be enough to buy a car would create. (How would you buy a candy bar?)
Second, while deflation would provide an incentive for people to hoard a currency rather than spend it, it provides an equal incentive for people to try to pry that currency out of other people's hands by any means. If I'd rather hold my Bitcoins than spend them (so that you'd have to offer me more for them), you'd rather have my Bitcoins than something else (so you'd be willing to offer me more for them). It simply cancels out.
In order for a currency to be used to pay wages, and therefore widely used in general, the prices for goods that people buy would be fairly stable. Otherwise, people will reject the currency. Perhaps more importantly, employers will not agree to pay workers in a currency that is appreciating in value, as this would require them to lower wages constantly, something workers will not accept.
If we lived in a world with stable currencies rather than inflating currencies, you could make this very same argument to show that people would never agree to be paid in dollars, because that requires them to get constant wage hikes, something employers will not accept. But they do. So this is pure speculation that is against the evidence. Employees accept inflating currencies, there's no reason to think employers won't accept deflating ones.
Falling prices will cause people to delay purchases, and is symptomatic of lower demand in general. This causes a depression. The example of computers given by many respondents is wrong. This is a case where new, higher quality models are replacing older models at the same price-point. It would be correct if the overall amount of money spent on computers (new and old) declined, but this is not the case.
Again, if we had a stable currency, this same argument would be used to show people will never accept the dollar. Why would anyone sell me anything today if they can sell it for more tomorrow? Don't rising prices cause people to delay sales?