That's really not a big deal. If it was truly popular and highly priced relative to everyday purchases, we'd just invent names for fractions thereof, and use those for pricing, as we do in reverse for currencies like dollars or pounds. They already have satoshis etc.

Far more important limitations:

Built in deflation - that it is seen as a one-way bet with ever-increasing value and an ever more limited supply would cause problems if used as a currency (though not obviously as a store of value). The problem for it as a store of value is that the value is entirely predicated on it being a successful currency.

Volatility - if prices change rapidly, that would make use in retail almost impossible, and as a store of value dangerous. Many of the places which say they take Bitcoin right now simply move the money immediately to another currency to avoid this issue - that's not going to work if it is actually used as a currency and to store value long-term. Imagine it replacing the USD for example and remaining volatile...

Time to process transactions - takings minutes to verify a transaction is not going to work -it'd need to be on the order of seconds, and for a digital currency it really should be as fast as the network.

Lack of regulation - again retailers/consumers should be nervous if their financial institutions have no regulations or guarantees that the money they say they hold actually exists at all. Some exchanges have reported a massive theft and walked away with no liability, others impose arbitrary limits on withdrawals etc - this really is wild-west finance and in a crash or bubble you can expect extreme fraud to go on undetected because there are no independent auditors, regulations or laws which govern these activities.

Lack of ties to identity - without verified accounts it's far too easy to commit fraud or theft - very like paper money which everyone is moving away from.

Lack of reversibility - it doesn't let you roll back transactions, though one could work around this by keeping a ledger and rolling the ledger positions back by transferring coins back and forth. If you're going to do that though and trust the bank/exchange to regulate transactions, why bother with the cryptocurrency bit at all?

Lack of transparency in the management process - who decides on the rules of the game here? If the official clients suddenly change rules in concert - existing bitcoin holders would have to just go along with this if the majority voted with it - when large amounts of money are involved, this sort of thing becomes very important. e.g. we hit the existing 21m limit, and those controlling the software decide to up the limit to 30m - suddenly lots of assumptions about value would be questioned. I'd be very nervous about the lack of regulated control.

Lack of backing by a government, corporation or trading bloc - when the market attacks government currencies, governments are able to expend extreme resources to mitigate outright panic and collapse. When the market sharks get interested in Bitcoin and attack it in the same way as they attack say the Euro, there will be no such backup, just a freely floating rate which is open to manipulation and depends entirely on public confidence.

I do think it has some interesting properties and is a useful experiment, but have extreme reservations about this being the actual digital currency which makes it into use as a global exchange mechanism.