The same is true of any foreign currency. I could send $150 million in Russian rubles to my sister, and she wouldn't be able to do jack with it until she finds someone willing to give her dollars for it. With the amount of money involved, getting it all converted at once would be extremely difficult.
That doesn't mean that what's transferred doesn't have real value. Just that the assets involved aren't terribly liquid.
That's exactly the point. If you had $150 million in rubles, you could transfer it for only a nominal fee ($20 for my bank, although you can get a lot cheaper if you regularly did transfers like that) to any account in the world that could hold rubles. Exactly the same with bitcoin.
The only real cost in transferring sums of money is either extreme convenience, transferring to a country with an extremely poor banking service or exchanging currencies. None of which bitcoin solves yet.
I have no counterproof, but I find this hard to believe.
http://www.stgeorge.com.au/online-services/business-banking/...
Telegraphic Transfer (TT) Request $20.00 per transaction or item
Pretty sure that would be fine up to ~$1 million. Anecdotally I know TT happen for sums in the range of $10-$100 million (there was a case where ~$150 million was stolen by a rogue TT in Australia to overseas bank accounts).
Source: Someone I trust who works in Private Client Services at JP Morgan (not sure if other banks offer free wires, but I'd be surprised if they don't).