In my home city there are a few software companies, even a major games studio, but no real community - there's a Linux User Group peopled by beardy academics, but nothing more.
In the next nearest city, there are tech events every night of the week. There's a hacker space open and another being planned, startups sharing offices and the general buzz of stuff happening. The networking opportunities are absolutely immense - in any given week you could meet the founders of two dozen startups, easily.
What do you think my odds are of getting a great job in each city?
OP is wrong, absolutely dead wrong. Yes, there are opportunities outside of major cities, but they're much fewer and further between. There's an argument that competition is less fierce outside of metropolitan areas, but it's a bad argument for two reasons. First, it smacks of a poverty of ambition, a "good enough" attitude that no young developer should sink to. The other is that it isn't true. There is absolutely massive demand for good developers. Recession or not, most firms are desperate for people who really can write software.
While I'm sure you can build a good career in software anywhere, it's going to be an uphill struggle if you're not surrounded by people who are doing the same. There is a reason that companies are still spending fortunes building skyscrapers - proximity matters.