SMS trojan threat demonstrated?

An interesting piece here regarding one of those proof-of-concept mobile security threats (none of which have yet come to pass). This one's from a guy called Wilfried Hafner, CEO of SecurStar (who is of course punting his company's products, but still...). It's a trojan called RexSpy and it's an SMS that looks like a security update from your operator, only what it does is let the sender eavesdrop on your conversations, check your SMSs etc.

All very nasty, but not in the real world yet. However, what is interesting is the operators' inability or unwillingness to explain what they intend to do about the fact that phones can't verify the senders of such messages. A poor show, and one to keep an eye on.