I'm against muni-provided connectivity for three reasons. And none of these apply to things like "police" or "fire", so let me explain why the typical analogy to "public services" doesn't apply.
Without "billing", there's no accountability. If I can get free connections, I can send spam to my heart's content, and you can't turn me off, because I can quickly become "another free user" in a matter of microseconds.
And I can start p2p-sharing my child pr0n and ripped movie and song collections, and again, you can't turn me off, because I don't actually have a contract with you to terminate. Sure, you can arrest me, but you have to find me in the mesh. It's not like you have a street address for me. Heck, I might even be operating from a van that constantly drives around.
Whether we like it or not, when citizens start paying for shipping bits, they're gonna want some say in the kinds of things that are being shipped across the wire. The moment the soccer mom figures out that part of her tax dollar is paying for that creepy guy over there to download his pr0n, she's gonna be storming city hall. And she's also going to be complaining loudly when she finds out that her son can access all sorts of evil things "over the city's wireless system!" She'll want controls put in place, and rightfully so. After all, she's paying for it.
As evidence, look at the constant tug-of-war and lawsuits regarding internet access at public libraries. Do you really want to open this up on a city-wide scale? It's the very same issue.
So, no matter how "open" some of us want this, it's going to start getting filtered. We'll never have a truly censorship-free mesh, except for perhaps the first six months. And if there's a constitutional challenge that comes down to a free-speech thing, it'll more likely get shut off than opened back up.
OK, you say. Then if there's enough demand for an uncensored equivalent, some private sector can come along and provide a different mesh that provides the full bits.
Well, that's ignoring the economics of the situtation. To deploy a city-wide private sector net requires a fairly large infrastructure, and that can only be supported by having access to a large customer base. But most of the customers of the "free" citywide net won't be buying, because for them, the "free" net is almost good enough. This is false economics, because they're effectively being subsidized $10 a month by the city's taxbase, and if they had to choose between that and a $15 "get everything" net, they might make a more rational choice.
So, for these reasons, I say that cities must stay out of the wifi business. As much as I'd like "free" wifi, there's no such thing as a free lunch, and as soon as someone realizes they are paying for it, they'll want to control it.
I'd much rather have a few companies vie for my $15, than for me to get censored, slow, no-choice free service.
Disclaimer - I pay $60/month for Verizon's EVDO service. I'd still have that in every city, regardless of what they do. I'm speaking more for the friends of mine that can't justify that sort of cost.