I really think that most people seem to expect too much from Bitcoin. Maybe it's because of the name which seems to suggest something similar to euro or dollar and implies it should behave the same.
At its core, Bitcoin is a technical protocol to make financial transactions without any central authority to confirm that they really took place. As such, it performs nicely (clunky, enormous blockchain seems to be a problem, though). Transactions are almost impossible to be traced (because you can generate new accounts without any problem) and no one can freeze your assets, which makes it handy not only for black market transactions, but also for supporting sites similar to Wikileaks. Oh, and some grey areas, like online poker or porn. Tinfoil hat-types who hate credit cards can also benefit from its existence.
I don't know how the protocol would work if it were tied to a real currency, instead of creating an entirely new one, but I can see some benefits. It's nice that its actually harder to pull a shitload of money out of thin air and everyone knows how much coins there is in any given moment. Giving money to the people who encrypt blocks makes sense, even if it means that early adopters probably wallow in their virtual currency right now. Still, it makes for a strange economy which by no means resembles the one we know.
Obviously, it won't be backed by anything in our lifetime, but frankly I'm not sure why it should. It is sufficiently scarce - the algorithm doesn't let to just spawn bitcoins and, as far as I know, it still hasn't been cracked. Moreover, its scarcity is more predictable than anything we know. No one is going to strike a motherlode and inflate the currency. It's really hard to make them from nothing silently. All transactions are saved in the block chain, so if someone is hoarding a huge stash, it's quite simple to detect.
The price volatility is a problem, but not it's not crippling if bitcoins are used as they should. I'm baffled why so many people seem to treat them as an investment - mostly because hoarding cash has never been safe or particularly fruitful, not even with euro or dollar. It's safer to either convert or spend them immediately after transaction. Speculation is like Vegas, only without booze and hookers.