DC Streetsblog has an article on the subject.
In short, while Missing Persons may have been correct that "Nobody walks in LA", Nobody should walk in Florida. As a pedestrian myself, I am pleased metropolitan Minneapolis is ranked 48 (which is relatively good) out of 52 US metros above 1 million population.
As with Bicycles, it seems the more people who walk to work, the safer walking is. (And the causation is likely to be mutual).
It is interesting to note:
Pedestrian fatalities have fallen at only half the rate of motorists, dropping by just over 14 percent during the period.
Two major reasons auto fatalities have dropped is safer vehicles (airbags, crash resistance, etc.) and better emergency medicine and response time. Clearly only the latter would play into pedestrian fatalities. These numbers suggest each factor is about equally important in the decline.