Interesting post from Jan Chipchase on Future Perfect. Hutch in India apparently offers a blanket opt out for sending commercial text messages through to your phone.
Jan frets about the 72 hours before the block will be in place, and the unspecified time it will take for Hutch's marketing clients to comply.
If Hutch gets this right (that's a big if), client compliance should not be a problem. Mobile providers, after all, are known for 'keeping the keys to the Kingdom', allowing their customers access only to those bits of cyberspace they make money off, and generally blocking the kind of progress we've seen on the wider Internet. But that should work both ways.
The flip side of the medal is the provider's responsibility to shield their customers from unwanted communications. Either accept that responsibility, or take you hands off the whole thing and let your subscribers roam freely across the Web.
Unfortunately this logic does not appeal to telcos, judging by their initial reactions in last year's mTouche scandal in Singapore.