I don't want to speak too soon, but this morning it feels like a tipping point has been reached. Last night was not an escalation, but a calming - at least in London - and the police are starting to identify individuals. Last night, they raised the policing in London from 6000 officers on monday to 16000, drafting them in from elsewhere. As a result, London seems to have had no incidents last night though there were some in Manchester, Salford, Birmingham, Liverpool and Nottingham. Again, whilst terrible for residents, I don't think it's anything a tourist would be affected by (after all, a resident is tied to a place, and a tourist could simply get up and go). These places are still large cities, but it they are all much smaller than London, and so logistically it is tougher for the yobs to move from one place to another - and so it should be easier for the police to deal with. The key is London.
As I've said before, my wife commutes to London, and I went in myself on Monday (and will do so again soon). Central London is a world away from Brixton, or Hackney, or Croyden.
One weird thing is that on Monday, when I was in London, I felt totally fine - the newspapers could have been describing somewhere else entirely, however, on Tuesday, when my wife was in London and all I could see were the media reports, I was much more concerned. However, @bobbyllew was in on tuesday, and he had the same experience I did on Monday.
Just got back from old London town, have to say, where I went (central) there was absolutely no sign of anything rioty
It's difficult to remember when seeing terrible pictures, but the media will chase the trouble - that's what makes the story. They will show 'where it is unsafe', forgetting that the vast majority of places don't fit that description.
If you've flights booked to the UK, and you want to avoid the big cities, there are many options. Try the Lake District or the West Country for instance. You could go to Norfolk and spend a week pottering on the Norfolk Broads. Indeed, these would be good options at any time - and are areas where you won't see many tourists from abroad usually. A place not far from where I am now is the Jane Austen museum. This is somewhere that's popular with Americans - and it has a nice tea room opposite. Or perhaps, if you want a town visit, try Bath. This is a very well appointed town with some lovely Georgian architecture as well as a geothermal spa and a great rugby ground (although my team is Wasps).
What I'm trying to say is, if you've flights to London - you'll probably be fine if you're in central London, but if worried, take the flight but change the location within the UK. See something else, something that wouldn't normally be first on the list for a visitor from your country.
Returning to relevance: The Guardian has put together a map of the issues. On this map, a red blob is something that has happened in the previous 24 hours, a white blob is something older. As I type, London is in white.
I don't think we're out of the woods yet, but I have the sense that the worst is behind us. Fingers crossed.