Reading a report in the FT about the rioting, I spotted the word "belatedly" in relation to David Cameron's response. It's a word also used a lot in terms of his response to the phone-hacking scandal and the NHS reforms. I think it is becoming a perception - at least in the commentariat - of his style of government.
The Right (understandably) ranks his ability to put on a good public performance. But it is noticeable that now for the third time on a big issue this has come after a prolonged period of drift. One to keep an eye on.