The value for residents is clear. The value for the town is sort of clear, even if it makes a mess of their budget. The value for businesses, however, starts to get murky.
Consider this. What do you do if you're a Portland area business and you've already spent thousands of dollars putting up your own 802.11 network? You invest in the hardware, the management software, and you pay engineers to map out and plan the best coverage to eliminate any RF interference. Then, the new, municipal network comes online and interferes with yours, causing mayhem. Do you have your partner come back out, re-align everything and then send the bill to the town? And what about security? If you spend the money to make your system secure (as any responsible corporation should), what do you do about employees who what to stroll downtown on their lunch break with their laptops and tap into the unsecured, free muni system and leave their machine and potentially your network open to attack?
This is why enterprises have to be ultra vigilant about their employees' use of any wireless system, free or not, good for the community or not. Speaking from experience, I've been on trade show floors where dozens of Wi-Fi networks are crackling away, and it's surprising how few of them are secured. Same goes for walking around town. From my office in Manhattan, I could see usually about 10 Wi-Fi networks, some of them coming form the apartment building across the street and others from several area businesses, and none of them were secured.
Enterprises have to be more careful than that.
With wireless access sprouting up all over, the problem is that it is becoming an expected service, like electricity or water. People expect it to be there like their utilities, and they expect to be able to use it for free. The free model, while completely cool, is more of a threat than you might think.