I was thinking there of how the area around Racine is starting to attract people from northeastern Illinois who don't want to drive all the way to Door County. Not as big a destination, no, and probably never will be, but it's something.
That being said, it's definitely a developing area and becoming more urban. Oak Creek especially is becoming very nice. In 30 years or so, it would not surprise me if that whole stretch of 94 between Milwaukee and Chicago became urbanized.
Go take a look in the marinas in the counties between Milwaukee and Chicago. A lot of Big City money floating in those communities (and in condos/houses along the lakeside).