I'm a little late to this topic, but I have to agree with what @Mark Shaffar is saying in his last post. If I went all out purchasing foreclosures in California in the down turn, I'd be a pretty wealthy guy right now :). I learned about investing here on BP and was taught to focus on cash flow first, appreciation as a bonus to be safe. I started out that way and missed that boat here, but not in Milwaukee. I feel a little more knowledgeable about how things operate now where I'd be willing to purchase something local in the event of another price correction if it makes sense though. Maybe when I'm at a different stage in my investing, I'll be more open to more long term wealth-building plays. I'm just trying to leave my job for now though!
Like @Dawn Anastasi mentioned, there are different areas of the city, like any city, that are better to invest in that wouldn't be AS affected by certain macro-economic changes.
Despite the article listing MKE as place people are leaving, we're experiencing some appreciation in MKE right now. Maybe because of the influx of investors? Not sure, but it's there. The city is currently doing a lot of "projects" to spruce things up, which they weren't doing 2 years ago. Dawn and I were just chatting about how there are some apartment buildings being majorly renovated and even some new ones in the works to be built.