London - the city that will be.
Here are some alternative tag lines that mean the same thing.
- London - the city that sucks ass now but might be OK someday.
- London - please return in 20 years.
- London - pretty much not even a city.
It's almost as bad as some U.S. state slogans. Wisconsin - "Stay just a little bit longer" (please?); "Oklahoma is OK" ; Louisiana - "Come as you are. Leave different" (i.e., this state will fuck you up good).
I hope DeCicco-Best isn't failing to see the forest for the trees in the place formerly known as the Forest City. London has its problems, but overall I think it's pretty OK.
PRO TIP: Hope for the future doesn't require implicit derogation of the present.