Yeah, it's a very nice way to get around this well known problem. However what surprises me most is that if they ever want to be adopted on a large scale the clients ought to be better than this. ALL TRACE of your money is stored in a single file (wallet.dat) and there is no way with the default clients to back it up and encrypt it (very easy to do with dropbox etc). In real life we never carry all our money with us and we can block our credit cards should these be lost...