As far as major American cities with employee medical costs are concerned, a bunch of them are looking at putting employees on Obamacare in order to save local taxpayers millions, starting with of course Detroit:

As Detroit enters the federal bankruptcy process, the city is proposing a controversial plan for paring some of the $5.7 billion it owes in retiree health costs: pushing many of those too young to qualify for Medicare out of city-run coverage and into the new insurance markets that will soon be operating under the Obama health care law. 
Officials say the plan would be part of a broader effort to save Detroit tens of millions of dollars in health costs each year, a major element in a restructuring package that must be approved by a bankruptcy judge. It is being watched closely by municipal leaders around the nation, many of whom complain of mounting, unsustainable prices for the health care promised to retired city workers. 
Similar proposals that could shift public sector retirees into the new insurance markets, called exchanges, are already being planned or contemplated in places like Chicago; Sheboygan County, Wis.; and Stockton, Calif. While large employers that eliminate health benefits for full-time workers can be penalized under the health care law, retirees are a different matter. 
That's probably the best way forward for Detroit, frankly.  I don't like it, but it's better than the alternative:  no health care.  And once again, the more people making a success out of exchanges, the more people will use them.  Eventually, we'll be getting to a single-payer model.  But for now, Obamacare's exchanges are going to be where health care is going to go over the next several years.